Green Earth Co. Melbourne, Florida
Greenhouse and Hydroponic Supplies and Wholesale Supplies prices to retail greenhouses and Growers.
There are many aspects to consider before sowing the first seed or purchasing the materials to build a
greenhouse. Careful consideration of the many factors involved in a commercial greenhouse can save many hours and dollars
in losses. While you can't plan for everything, a well-thought-out plan can help plot a course as the business grows.
A large percentage of small businesses fail within the first 2 years. Complete as the information in this document may seem, it is
designed to provide general guidelines for starting a greenhouse business. Spend time reading as much material as possible to
prepare for operating a business. Experience is a good teacher, but preparation can help avoid costly mistakes.
Reasons for Starting a Business: Your Motivation
Many people look at a business and think, I can do a better job myself! Many new businesses are established with this spirit. But
what are good reasons for wanting to start a greenhouse business?
Sometimes an individual sees a real need for highquality plants in a town or area. Another individual may see a need in the
market for specific kinds of plants, such as rare herbs or herbaceous perennials. These opportunities for profit are solid reasons
for motivating an individual to consider establishing a greenhouse business.
Another reason is a love of plants. While it is important to enjoy your work, a love of plants cannot make you a good
businessperson. Remember that the real reason to establish a business is to make a profit. If you cannot show a profit in several
years, the business may no longer be viable.
Are You Ready for Your Own Business?
After considering your motivation for starting a greenhouse business, consider your personality characteristics. Many people want
to start a business because they want to be their own boss. Many entrepreneurs who start businesses will tell you that you are
not the boss. The banker becomes a boss if you borrow money. Customers become the bosses because you must satisfy them.
While there may not be any one person to report to at work, going into business for yourself means you now have multiple
bosses.
What characteristics do you have that will make you a good greenhouse grower and a good businessperson? The answers to the
following questions may help determine if you are ready to strike out on your own.
Are you action oriented? Can you make decisions after considering the facts at hand? Business people often don't have all the
facts needed to make a black-and-white decision. Decisions frequently must be made under pressure. Can you get the job done?
Are you results oriented?
Are you dedicated to success? Can you work long hours, often 7 days a week when necessary? Greenhouse plants must have
attention every day. During some seasons, the work can be 70 hours per week or more. You, as the boss, must be prepared to
commit the time and attention required. You must be dedicated to getting the job done. You should also learn from your failures
and not get discouraged.
Are you a manager? Can you delegate assignments to employees or do you need to do everything yourself? You cannot do
everything yourself if you are the boss. You must hire competent people as part of your team and give them responsibility to get
jobs done.
Are you a good planner? A manager needs to plan for growth in the business, plan when to plant and harvest crops, and plan for
unforeseen challenges such as cold temperatures in the greenhouse or crops that are not ready at harvest.
Do you have the appropriate knowledge and experience? Have you grown the crops you plan to sell? Have you ever operated a
business before? It is better to learn (and make mistakes) by working for another greenhouse and get some good experience
before starting your own business. While a college degree in business or horticulture may not be required, there are many things
you will need to know concerning crop culture, greenhouse operation, people management, sales, and the day-to-day operation
of a business.
Do you have enough resources? Do you have enough money to start and operate the business while you get established and
until you can pay your own bills? What other resources do you have and are willing to risk on the success of the business? Will
you qualify for a loan? Who will give you a business loan?
Do you have people skills? How well do you work with people as the boss and as a salesperson? Can you interview, hire, and fire
someone? Can you handle employee and customer complaints? Managing a business involves managing your time, other peoples
time, your customers complaints, and your suppliers, as well as your banker, attorney, accountant, and financial planner.
Are you flexible? Can you adapt and grow as your business grows? Are you innovative enough to contribute to the expansion of
the company? What will customers want next year? Where will the market be in 5 years?
Analyze yourself carefully to make sure you are prepared for the challenges. Not everyone is made to own a business. Not
everyone has all the skills needed to operate a business. Identify the skills and strengths you have and determine if you can hire
another person or several individuals to make up for your weaknesses.
Where Is Your Market?
The marketing process includes a range of activities intended to identify and satisfy the desires of consumers while earning a
profit for the business. These activities include identifying customer needs, developing products and services to meet those
needs, establishing promotional programs and pricing for the products and services, and implementing a system of distribution to
the customers. It is essential to identify and understand the market, know who the competition is, and develop a market niche.
Remember, grow what sells, not what you are fond of.
Selling plants directly to consumers in a retail business is different from selling plants wholesale to garden centers or other retail
businesses. To determine if a consumer market is large enough, conduct a demographic study—a study of the characteristics of a
particular area. This should help you assess whether a greenhouse business is feasible. Characteristics that should be of interest
are population, projected population growth, age distribution, income levels, age of community, number and size of residential
areas, types of housing and lot sizes, trade areas, gross retail sales, unemployment rate, and major employers. Some important
questions to consider are the following:
Do enough people live or shop in the market area you choose?
How much competition do you face?
Are a lot of other businesses already growing and selling the products you would like to produce?
If you will sell plants to a wholesale market:
Are there distributors or wholesalers who could purchase your plants?
Can you sell directly to retailers in your market area?
Are there enough retailers who could purchase your products?
What advantages, such as higher quality plant material, a broader product mix, or improved services, can you offer retailers to
encourage them to purchase plants from you rather than from their current suppliers?
You need to understand the market, how it looks today, and how it will look in 5 years before deciding to go into business. It may
be difficult to collect enough information about the market to make a decision. The local chamber of commerce may be able to offer
assistance. Ask the local library for additional information. The telephone book is an excellent resource when assessing the
competition. Take a little time to look for sources such as census reports, demographic studies, newspapers, and the World Wide
Web. Other very good information sources are real estate agencies and the county Extension office. Be creative to find as many
facts as possible to help you make decisions about the market.
Characteristics of the markets will have an impact on the type of marketing you choose. Plants can be marketed at wholesale,
retail, or, in some cases, mail order. Wholesale production greenhouses sell relatively large amounts of products to a small
number of accounts. They may sell to florists, independent garden centers, grocery stores, mass merchants, home centers,
landscape businesses, or grounds maintenance firms. Many wholesale greenhouses grow a wide range of products throughout
the year for daily, seasonal, or contract sales.
A retail greenhouse sells a relatively small amount of products to a large number of individual customers. This type of operation
generally requires high product quality, active marketing, and superior service to succeed. Many retail merchandisers do not grow
plants, but purchase all or most of their products from wholesale growers. The greenhouse serves to maintain plant health until
sold, not to increase plant size. Retail growers produce a variety of plants to sell from their own retail operations. Because it is
often disruptive to have customers selecting products in a production facility, the retail facility is often separate from the
production facility. The retail facility may be at the same or at a different location.
What Type of Business Will You Establish?
Another consideration in starting a greenhouse business is to decide how the business will be structured legally. Usually, the
business is structured in one of three ways: sole proprietorship, partnership, or corporation. Each legal structure has several
advantages and disadvantages. Consult an attorney and accountant to decide on the structure that best suits your needs.
Most entrepreneurs start in the sole proprietorship legal form of business. The primary advantage of this form of business is that
you, the sole proprietor, are responsible for the assets and liabilities of the business. You are the boss. You have complete
liability, and you are taxed personally for the profits of the business. However, your personal and business assets can be taken
away if the business has financial trouble and you owe creditors money.
A partnership, with one or more partners, is another type of business with some different advantages and disadvantages. A
partnership may have more resources and partners sharing the responsibility and the liabilities, but you have at least one other
individual that you can consult regarding business decisions. Some people find this a great advantage because one person may
be good at growing plants and the other may be good at operating a business. This interaction can work to the advantage of
both. Like the sole proprietor, all partners are liable for the business's assets and their own personal assets can be jeopardized if
the business has financial difficulty.
The corporation is the third form of business structure. Today, more greenhouse businesses are corporations because of the
advantages a corporation offers. Unlike the sole proprietorship and partnership, the corporation is only liable when financial
difficulties arise. Only the business assets can be taken if creditors demand payment. The primary disadvantage to a corporation
is that the business is taxed twice: one time on the profits the corporation earns and a second time when the owners of the
corporation receive personal income from that corporation.
Where in Your Market Will You Locate Your Business?
Location of the property in the market area will affect the success of the business, especially if it is a retail business. Study the
market to determine the best location. Real estate agents will tell you that the three most important considerations for a retail
business are (1) location, (2) location, and (3) location! For a wholesale business, access to the market is more important than
the markets (your customer) access to you. When considering where in the market area to locate a business, think about the
following.
Size and shape. The exact size and shape of the property will depend on what size business you are planning to start and the
layout of that business. However, a minimum of 3 acres is recommended. In general, property with more road frontage is more
expensive, but it is also more visible to customers. Plan for expansion. Is there enough room to grow in the next 5 years or so
until you can afford to purchase more property for the business?
Zoning regulations. Make sure the property is zoned for business. Check to see if zoning is likely to change in the near future or if
it has been disputed in the recent past. Are there any special restrictive clauses that may inhibit your expansion? Are there
regulations on the size or height of signs that can be used to promote your business?
Accessibility. The business should be close enough to major roads for delivery and transport trucks to have easy access. Are there
any weight limits or restrictions on large trucks? For a retail greenhouse, locate the business so customers can see it from at least
200 feet and can get to the business easily and safely. Plant shopping is often done on impulse. If customers have to cross major
barriers or make a special effort to get to your business, chances are they won't.
Labor availability. Operating a greenhouse business is labor intensive and obtaining experienced, dependable labor can be
troublesome. Readily available labor and support facilities should be within 20 minutes drive of the greenhouse site. Is there a
good source of skilled labor in the area, such as a high school program with horticulture students, a university, college, or
technical school? Also, extra unskilled help will be needed during peak business times. Good sources of extra, part-time help are
high school students or older, retired adults. Labor should be available at a price you can afford.
Water quality and availability. Is city water available or will you have to dig a well? If you dig a well, how much water is available
and how long will it last? Many greenhouses require about 6 acrefeet of water per year for every acre of greenhouse production
area. Regardless of the source, have a water quality test performed. This is an inexpensive, easy procedure that may save a lot
of money in the future.
Private labs or your county Extension agent can help take the water sample and have it analyzed. Check the level of soluble salts
and bicarbonates. Low soluble salts, a level below 0.75 mmhos/cm, is best because fertilizer is often added to the water during
irrigation. When present in excess amounts, some salts are toxic to plants. Water bicarbonate level is important in plant
production. A bicarbonate level of less than 100 ppm (parts per million) is recommended for growing most plants.
You will also need a plan for water collection and a plan for water runoff from your greenhouse.
Utilities. How many are available, and what are the connection fees? You will need electricity and, depending on other equipment
and needs, you may need gas, water, or sewer services connected. Check with each supplier to determine costs and to anticipate
any difficulties they might have in supplying services.
Taxes. What is the tax rate on the property? Are taxes likely to increase substantially in the future forcing you to move the
business elsewhere?
Local building codes. What codes will affect which buildings you construct and where on the property you locate them?
Neighboring businesses. What affect will other businesses have on traffic flow of customers into and out of your business?
Natural slope and drainage of the land. Grading land can be very expensive. Greenhouse structures should be located on a slope
of 5 percent or less. Avoid locating a greenhouse on a flood plain, in a frost pocket, or on a hilltop where heating costs will be
high. Avoid an area where nearby structures or trees will cast shadows on the greenhouses.
Resale value. Someday it may be necessary to sell the property, for good or bad reasons, so have an estimate of its resale value
in the future.
Your Business Layout
In a wholesale production greenhouse, the primary factor to consider in arranging buildings and equipment is materials flow and
how it impacts labor utilization and future expansion. How will materials come into the facility (delivery and unloading), be stored
until needed, and be moved through the production process? How will products move out for packaging and be delivered to
customers? Labor is often the single largest expense in a greenhouse business, therefore, materials movement and handling
should be arranged to minimize the labor required. One possible arrangement is shown in Figure 1.
Materials flow is also important in a retail operation, but customer movement and access are also critical. How will products move
from delivery trucks to the display area, from the display area to the checkout register, and from checkout to the customers
vehicle?
What type of structures or areas do you need to start the business? A production facility and several other areas might be useful.
Some examples of specific structures and areas to keep in mind when considering the construction of a business are the
following: greenhouses, shade houses, work area, soil mixing area, storage buildings, pesticide room, roadways (large enough
for trucks), parking facilities, sales room, offices, landscaped area (display garden), break room/kitchen, rest rooms, cashier
location, loading dock, and shipping area. The sizes of each of these specific areas depend on plans and goals for your individual
business.
Greenhouse Styles
Generally, there are two styles of greenhouse layout commonly used for new businesses: detached or freestanding houses or
ridge and furrow or gutter connected houses (Figure 2). Detached greenhouses stand independently and may be constructed
using different greenhouse types (gable, Quonset, etc.). Access from the work area to the greenhouses is often through a
central, covered corridor or uncovered aisle. This layout style is common for small growers who are starting with 10,000 square
feet or less, but who plan to add houses as the business grows. This style has advantages and disadvantages. Each house can
be controlled by its own heating/cooling system to accommodate crops requiring widely different environments. Efficient
movement of people and materials, however, can be a problem, especially in inclement weather.
Ridge and furrow greenhouses are connected at the eave by a common gutter. Different types of greenhouse construction can be
used for a given row of connected houses. Internal walls may separate individual greenhouse sections where crops require
different environments or internal walls may be absent where large, single crops are to be grown. Some advantages of the ridge
and furrow style are lower construction costs compared to detached houses, especially for future expansion, lower heating costs
per unit compared to detached houses, and more efficient movement of people and materials.
Greenhouse Types
The most common greenhouse construction for most new businesses is the Quonset type (Figure 3). These houses are
constructed with arched rafters covered with one or two layers of flexible plastic, usually polyethylene. One disadvantage of
polyethylene is that it is subject to ultraviolet light degradation and must be replaced every 2 to 3 years. The cost of construction
for detached houses is lower than the cost for other greenhouse types, usually $2.75 to $3.25 per square foot excluding heating,
cooling, and benches. Many new businesses start with one or more houses that are 25 to 40 feet wide and 90 to 100 feet long.
However, this type of construction can be applied to either the detached or the ridge and furrow styles.
Many greenhouse construction companies offer packages for constructing Quonset greenhouses. These commonly come with
either steel or aluminum bows and the manufacturer specifies the bow spacing depending on the structural strength of the bow
material. However, before purchasing, select the frame based on load-bearing requirements. This will be determined by whether
or not the structure will support equipment or crops. Hanging the heating system, irrigation equipment, or hanging baskets from
the framing will increase the load-bearing requirement. The end walls are often constructed of wood or metal framing covered in
polyethylene or rigid plastic with aluminum doors for access. The side walls are often wood or metal with special fasteners for
holding the polyethylene in place. The foundation for a Quonset greenhouse is usually a concrete footing poured at intervals
dictated by the bow spacing.
Polyethylene manufactured for greenhouse application comes in 20- to 50-foot widths, 1 to 8 millimeters thick. It costs $0.12 to
$0.18 per square foot. Two layers of polyethylene are frequently applied to greenhouses to reduce heating demand. Double-layer
polyethylene houses generally cost 30 to 40 percent less to heat than do single layer houses. The two layers are kept air-inflated
using a 100 to 150 ft.3/min. squirrel cage blower mounted to the inside plastic layer. Purchase 4-mil plastic for the inside layer
and 4- or 6-mil plastic for the outside. Use 6-mil polyethylene for single layer applications. Polyethylene can be installed on wood
portions of a greenhouse by nailing wood batten strips over the film into the foundation boards and end walls. However, because
polyethylene will require replacing frequently, investing in special fasteners will make the job easier. Fastening systems are
available for single- or double-layer applications.
A second commonly applied greenhouse type is the even span, gable roof (Figure 3). This type of construction is appropriate
where rigid glazing materials will be used such as glass or rigid plastics. The cost of construction for glass-covered, detached-
style houses is higher than for Quonset types, usually $5.50 to $7.50 per square foot excluding heating, cooling, and benches.
However, these structures are more permanent and require less maintenance. Gable construction with rigid glazing is a good
choice when plans are long-term and the business is well capitalized. This type of construction can also be applied to either the
detached or the ridge and furrow styles.
Gable houses use galvanized steel, aluminum, or a combination of the two materials for constructing the frame. The weight of
glazing material, the weight of equipment attached to the frame, snow and wind loads, and the width of the greenhouse will
have an impact on the type and size of materials chosen, size and spacing of support posts, and the design and construction of
trusses. Glass is very heavy and requires strong support while rigid plastics are lighter requiring less support. Trusses and
support posts may be spaced 6, 10, or 12 feet apart depending on load requirements while roof and side bars are spaced
according to the width of the glazing material used. In recent years, eave heights have increased to 12 to 15 feet or higher in
southern greenhouse construction because taller houses ventilate better and stay cooler. Gable houses, especially those covered
with glass, should have a strong, concrete, or concrete block foundation that extends below the frost line according to building
codes.
Glass is the traditional greenhouse covering against which all other materials are judged. Originally, glass panes for greenhouses
were 18 by 16 inches, but larger sizes are becoming more common. Actually, larger panes are less fragile than are smaller panes.
Many greenhouses are covered with double-strength float glass (1.8-inch thick) costing $0.85 to $2.00 per square foot. Large,
glass panes and tempered glass may cost $3.00 to $7.00 per square foot.
Fiberglass reinforced panels (FRP) are rigid plastic panels made from acrylic or polycarbonate that come in large, corrugated or flat
sheets. FRP panels are available in 24- to 57-inch widths and up to 24-foot lengths. These materials are durable, retain heat
better than glass, and are lightweight (less structural support needed). Light transmission may be better than glass simply
because less structural support is needed, therefore, fewer shadows are created. The cost of FRP panels range from $1.00 to
$1.25 per square foot depending on the guaranteed life-span of the material.
Double-layer structured panels (DSP) are made from acrylic or polycarbonate and are constructed of two layers of plastic held
apart by ribs spaced 1 to 2 inches apart. The double-layer construction increases structural strength and heat retention, but
decreases light transmission compared to singlelayer materials. Panels may be 4 feet wide and up to 39 feet long. DSP made with
polycarbonate costs $1.75 to $2.50 per square foot while those made with acrylic costs $2.00 to $3.50 per square foot.
Floors and Walks
The type of floor for a greenhouse will depend on the type of production (pots or flats on the floor or on benches), available
capital, and soil drainage. Bare ground should be avoided because of potential insect, disease, and weed problems and the
presence of a muddy growing surface. Weed mat overlain with 4 inches of ¾-inch crushed stone or pea gravel will help control
weeds and provide a porous medium through which water can drain. Areas under benches can be treated the same way. If a
solid concrete floor is desired or necessary, install drainage basins and slope the floor toward the drains. Concrete aisles are
preferable where carts and wheeled equipment will be used. Walkways can be 2 to 3 feet wide in a small greenhouse. Adjust the
width of walks for wheeled equipment. Larger greenhouses often have 2- to 3-foot secondary aisles and 4- to 6-foot or wider
main aisles.
Benches
Benches may be constructed from a variety of materials and arranged in many different ways. Careful planning can result in 70 to
80 percent of floor area devoted to crops with fixed benches and up to 90 percent utilization with rolling or movable benches.
Rolling benches are designed to open an 18- to 24-inch aisle of work space at any location along a row of benches.
Supports for benches should be strong enough to hold a large number of plants and the largest container size anticipated. Wood,
metal pipe, or concrete blocks have been used as bench supports. The bench surface should be strong enough to support plants
without sagging, but open to provide water drainage and air movement. Spruce or redwood lath and 1-inch square, 14-gauge
welded-wire fabric or expanded steel mesh make a strong, long lasting, open bench top. Bench height should be 32 to 36 inches
and width should be 3 feet if against a wall or up to 6 feet if accessible from both sides. Benches can be purchased from a
manufacturer in a variety of sizes and construction types.
Ventilation
The purposes of ventilation are to exchange carbon dioxide and oxygen, to remove hot air, and to lower relative humidity. Forced-
air ventilation relies on electric fans controlled by a thermostat and a louvered intake vent. Fans pull cool air into the greenhouse
from the outside through an intake vent and warm, inside air is pushed out. Fans should be mounted in a waterproof housing
with exterior, air-activated louvers to protect electrical components from inclement weather and to keep cold air out during the
winter. It is important to install a screen over the inside of fans to prevent injury. There should be a distance equal to at least 1.5
times the fan diameter between the fans and adjacent structures. The intake vent on the wall opposite the fans can have an air-
activated or motorized louver. Fan capacity should be large enough to exchange the air in a greenhouse at least once per minute.
Recommendations for warm climates call for a fan capacity to remove 12 to 17 cubic feet of air per minute per square foot of floor
area.
Natural ventilation has made a comeback in the South in recent years in the form of retractable-roof greenhouses and Quonset
houses with roll-up side walls. Retractable-roof greenhouses come in a variety of types while roll-up side walls on Quonset
houses are relatively simple. In both cases, the idea is to move as much of the greenhouse structure out of the way as possible
to expose crops to natural conditions during warm weather.
Cooling
One of the best ways to cool a greenhouse in the summer is to reduce light intensity. How much reduction to provide depends on
the heat load in the greenhouse and the light requirements of the crops grown. Greenhouse whitewash and shade cloth are
popular choices. Greenhouse whitewash is a special kind of latex paint that is diluted in water and sprayed on the covering
surface. This material is designed to be applied in the spring and gradually degrade by the action of rain and sun so that little
remains by fall. Shade cloth is a black, green, or white woven fabric of polypropylene that is applied over the outside of the
covering. Shade cloth can be purchased with various weave densities that result in 20 to 80 percent light reduction. For many
greenhouse applications, 30 to 50 percent light reduction should be sufficient.
Evaporative cooling relies on air passing through a porous pad saturated with water. The evaporating water removes heat from
the greenhouse. Fan-and-pad systems consist of a cellulose pad the length of one wall and at least 2 feet tall with water
supplied to keep the pad wet during operation. Fans along the opposite wall draw outside air through the pads. Fan-and-pad
systems cool more efficiently when the relative humidity is low, a condition that is infrequent in Southeastern summers. However,
a 5 to 10 degree reduction over the outside temperature can be achieved with a well-designed system.
Heating
Two popular heating systems for greenhouses are forced-air unit heaters that burn propane or natural gas and hot water or
steam central boilers that burn fuel grade oil. Unit heaters cost less in initial investment ($.30 to $.50 per square foot) than
central boilers ($1.00 to $2.50 per square foot), but cost more to operate ($1.00 per square foot versus $.60 per square foot).
Unit heaters are easier to install and require less maintenance than central boilers require, but even heat distribution can be a
problem. Central boilers provide even heat and combustion takes place away from the greenhouse, but installation can be time
consuming. Generally, unit heaters are more appropriate for small greenhouse ranges and central boilers for larger ranges.
Unit heaters burn gas in a firebox and heated air rises through the inside of a thin-walled heat exchanger on its way to the
exhaust chimney. A fan draws air in from the greenhouse, across the outside of the heat exchanger and into the greenhouse.
Thus, most of the heat is removed from the exhaust before it exits the structure. The exhaust chimney must be sufficiently tall to
maintain an upward draft and extend above the greenhouse roof. An 8- to 12-foot chimney is usually sufficient. Open flame
heaters must be vented to the outside and be provided a fresh air supply for complete combustion. Fresh air must be provided by
an unobstructed chimney to avoid carbon dioxide buildup and production of ethylene, both detrimental to plants.
Two warm-air distribution systems are popular for unit heaters: convection tubes and horizontal airflow. A convection tube is a
polyethylene tube connected to the air outlet of the unit heater, running the length of the greenhouse and sealed at the other
end. Warm air is distributed in the greenhouse through rows of 2- to 3-inch diameter holes on each side of the tube. Horizontal
airflow relies on a number of horizontally mounted fans 2 to 3 feet above the plants that circulate heat throughout the house.
This system as well as convection tubes may also be used at times when heating is not required, especially at night, to reduce
relative humidity and discourage diseases.
Central boilers burn fuel in a fire box to heat water to 180 degrees F or to steam in a heat exchanger. Exhaust smoke passes
through a flue to a chimney that vents exhaust to the outside. The heated water or steam is delivered to the greenhouse to
exchange heat with the air through pipe coils, unit heaters, or a combination of both.
Climate Control
Traditionally, the operation of heating, ventilating, and cooling equipment has been controlled by thermostats at plant level
located close to the center of the greenhouse. This system is still used effectively in small operations, especially those with
detached greenhouses. For accurate control, thermostats should be shaded from direct sunlight, preferably by mounting them in
a plastic or wood box ventilated by a small blower. Thermostats have the advantages of being simple, inexpensive, and easy to
install, but may be inaccurate and lack coordination with environmental control equipment.
Step controllers and dedicated microprocessors overcome the limitations of thermostats by providing more complex staging of
heating and cooling systems and by coordinating the activities of heating, cooling, and ventilating equipment. These units
generally cost from $800 to $2,500. Greenhouse environmental control computers add additional levels of control over
greenhouse equipment along with weather sensing, environmental data logging and plotting, and other functions.
Irrigation Equipment
Hand irrigation using a hose, water breaker, and wand is still one of the most widely used methods of watering crops for small
greenhouse operations. However, as the business grows, the cost in labor, the skill required to water effectively, and the logistics
of hand watering large crops become prohibitive. Many attempts have been made to utilize impact sprinkles to water greenhouse
crops, often with poor results. System design is critical to prevent wet and dry spots, excessive foliar wetting, and large volumes
of runoff. Boom irrigation is probably one of the most effective and uniform methods of overhead irrigation. Water is delivered
through fan-pattern emitters mounted on a rigid boom that travels back and forth across the greenhouse. Booms limit runoff
when used correctly, but crops must be reasonably uniform in size, age, and water requirement under a single unit to be
applicable. The cost of installing booms is probably prohibitive for most new greenhouse businesses.
Drip emitter watering is probably the most common type of automatic watering system. Water is delivered to each pot through a
small-diameter, polyethylene microtube held on the medium surface by a lead or plastic weight to keep the tube in the pot.
Multiple microtubes on a bench are supplied with water from a black polyethylene (usually ¾") header running down the center of
the bench and connected to a water main. Each bench may be turned on or off by a hand valve or electric water solenoid valve
installed where the header connects to the water main. Many benches or whole greenhouses can be divided into watering zones,
the size of which depends on the capacity of the water supply. Watering can be controlled by devices as simple as on/off switches
or as complex as an environmental control computer. Drip emitters deliver water directly to the medium surface at low volume
and, therefore, do not wet the foliage. However, their application is usually limited to 4- to 10-inch pots and crops must be
reasonably uniform in size, age, and water requirement under a single zone to be applicable.
Subirrigation involves supplying water by flooding to the drainage holes in the bottom of the pots. The water is absorbed by
capillary action upward through the potting medium. Capillary mats, gutter benches, flood benches, and flood floors are systems
that vary in complexity and cost. All share the advantages of being adaptable to a wide range of container sizes and have the
potential for recycling runoff water. However, monitoring nutrients, pH, soluble salts, and contaminants in closed systems requires
good management skills.
Fertilizer Injection
A fertilizer injector is a mechanical device that introduces soluble fertilizer dissolved in water (stock solution) into the water
pipeline for delivery to the plants. A wide variety of injector devices are available on the market with a range of capacities (gallons
per minute) and costs. Inexpensive units such as Hozon or Syfonex connect between a faucet and hose and suction fertilizer
concentrate from a bucket into the water line using the Venturi principle. These units have a fixed injection ratio delivering 1
gallon of stock in 16 gallons of water (1:16). These units are only useful for the smallest applications because the injection ratio
can vary with changes in water pressure and large volumes of fertilizer concentrate are required. Positive displacement units such
as Anderson, Dosmatic, Dosatron, Gewa, and Smith injectors cost more than Venturi types cost, but are much more accurate and
reliable and offer a wider range of injection ratios.
When choosing a fertilizer injector, match the correct model with the maximum water flow rate that the unit will be expected to
handle. The range of injection ratios available on a particular model will influence maximum daily water output and reasonable
stock tank size. Some applications require use of chemicals other than fertilizers, have need for separate injection heads for
incompatible chemicals, or present the problem of portable versus fixed installation. Consult the manufacturer to determine the
correct model for a particular application.
Crop Selection
What crops should you grow? How many should you grow? What does the customer want? Do your customers want annuals,
perennials, flowering plants, herbs, or ornamental grasses? What container sizes do they prefer? How many can they use? You
may have some idea about the types of plants you cannot find in the market. You may even have some idea about the types of
plants that may be in demand in the next year or two. There is no easy way to determine which crops to grow and how many, but
demand in the market should drive production. Only produce what you can grow at a cost low enough and sell at a price high
enough to make a profit.
The critical side of profitability is cost of production. The level of competition often sets the selling price. Know your cost of
production for each crop and select crops and production methods for profitability. The difference between cost and price—the
margin—must be large enough to operate the company, pay yourself a wage, justify the risk of being in business, and provide a
return on your investment. Grow the best quality product demanded by the market you are in. Do not sacrifice quality to lower
cost. Without quality, you will not survive in the market.
To get an idea of current trends in crops, read industry trade magazines such as Greenhouse Grower, Greenhouse Manager, and
GrowerTalks. Read homeowner and homemaker magazines such as Southern Living, Better Homes and Gardens, Woman's Day,
House Beautiful, and Family Circle. See what the industry is talking about in terms of new plants that may have desirable
characteristics such as good heat tolerance and disease resistance. See what customers are doing now by reading the
publications they read.
First consider producing the most popular varieties and then gradually introduce newer varieties or plants to customers. Add 10
to 30 percent new plant varieties each year. Remember that it is difficult for people to change anything, including the type of
plants they are accustomed to buying. The only way they will change is if you educate them. You will be looked to as the expert
for information and advice. Gather that information yourself and share it with customers. Plant the varieties you grow in a display
garden for you and your customers to evaluate. Visit other gardens to see how well plants perform under similar conditions. Visit
trial gardens to learn about new varieties and plan to include them in your production schedule in the future.
Another factor in selecting a crop to grow is deciding how to grow it. Crops can be started from seeds, plugs, or cuttings. The
propagation decision depends on the species, cost, scheduling and timing of the crop, available facilities and equipment, and
availability of seeds, plugs, or cuttings. Determine the cost of production using several different propagation methods and see
which is the most profitable. Your level of experience may also influence the best method to start a crop. For example, if you have
never grown bedding plants, starting with plugs will reduce the risk associated with germination, but it will increase the cost.
Eventually, you may want to produce plugs for your business to use or perhaps to sell to other businesses.
Complying With Alabama State Laws
Greenhouses need to be licensed by the state of Alabama to conduct business. Plants that are shipped out-of-state must comply
with any insect and disease quarantine regulations. For information on complying with state regulations, contact the Plant
Industry Section of the Alabama Department of Agriculture and Industries, P.O. Box 3336, Montgomery, AL 36193. Your local
Extension agent can also assist in contacting your county�fs plant industry inspector, who will inspect your crops and provide
additional information.
Keeping Good Records
Unfortunately, record keeping is an area of business that many new, small business managers neglect. However, keeping good
records is a simple task and in the long run can save time and money. A computer can make the task of record keeping easier.
Some records you will want to keep are the following:
Business records. Keep record of cash flow, inventory, income statements, and balance sheets. Any general accounting records
can be kept on a computer and will be available to assist in planning for growth of the business.
Employee records. A record of hiring dates, hours worked, rewards, and reprimands needs to be kept. Tracking hours worked by
employees can help in planning for seasonal needs and in seeing where the greatest labor needs are.
Crop scheduling. It is useful to record fertilizer applications on crops, planting dates, finishing dates, and other cultural practices
for planning future production and as a cultural reference. Legally, you must keep a record of pesticide spray dates, rates, and
chemicals used.
Customer records. Keep a record of names, addresses, and telephone numbers to contact past customers directly.
greenhouse. Careful consideration of the many factors involved in a commercial greenhouse can save many hours and dollars
in losses. While you can't plan for everything, a well-thought-out plan can help plot a course as the business grows.
A large percentage of small businesses fail within the first 2 years. Complete as the information in this document may seem, it is
designed to provide general guidelines for starting a greenhouse business. Spend time reading as much material as possible to
prepare for operating a business. Experience is a good teacher, but preparation can help avoid costly mistakes.
Reasons for Starting a Business: Your Motivation
Many people look at a business and think, I can do a better job myself! Many new businesses are established with this spirit. But
what are good reasons for wanting to start a greenhouse business?
Sometimes an individual sees a real need for highquality plants in a town or area. Another individual may see a need in the
market for specific kinds of plants, such as rare herbs or herbaceous perennials. These opportunities for profit are solid reasons
for motivating an individual to consider establishing a greenhouse business.
Another reason is a love of plants. While it is important to enjoy your work, a love of plants cannot make you a good
businessperson. Remember that the real reason to establish a business is to make a profit. If you cannot show a profit in several
years, the business may no longer be viable.
Are You Ready for Your Own Business?
After considering your motivation for starting a greenhouse business, consider your personality characteristics. Many people want
to start a business because they want to be their own boss. Many entrepreneurs who start businesses will tell you that you are
not the boss. The banker becomes a boss if you borrow money. Customers become the bosses because you must satisfy them.
While there may not be any one person to report to at work, going into business for yourself means you now have multiple
bosses.
What characteristics do you have that will make you a good greenhouse grower and a good businessperson? The answers to the
following questions may help determine if you are ready to strike out on your own.
Are you action oriented? Can you make decisions after considering the facts at hand? Business people often don't have all the
facts needed to make a black-and-white decision. Decisions frequently must be made under pressure. Can you get the job done?
Are you results oriented?
Are you dedicated to success? Can you work long hours, often 7 days a week when necessary? Greenhouse plants must have
attention every day. During some seasons, the work can be 70 hours per week or more. You, as the boss, must be prepared to
commit the time and attention required. You must be dedicated to getting the job done. You should also learn from your failures
and not get discouraged.
Are you a manager? Can you delegate assignments to employees or do you need to do everything yourself? You cannot do
everything yourself if you are the boss. You must hire competent people as part of your team and give them responsibility to get
jobs done.
Are you a good planner? A manager needs to plan for growth in the business, plan when to plant and harvest crops, and plan for
unforeseen challenges such as cold temperatures in the greenhouse or crops that are not ready at harvest.
Do you have the appropriate knowledge and experience? Have you grown the crops you plan to sell? Have you ever operated a
business before? It is better to learn (and make mistakes) by working for another greenhouse and get some good experience
before starting your own business. While a college degree in business or horticulture may not be required, there are many things
you will need to know concerning crop culture, greenhouse operation, people management, sales, and the day-to-day operation
of a business.
Do you have enough resources? Do you have enough money to start and operate the business while you get established and
until you can pay your own bills? What other resources do you have and are willing to risk on the success of the business? Will
you qualify for a loan? Who will give you a business loan?
Do you have people skills? How well do you work with people as the boss and as a salesperson? Can you interview, hire, and fire
someone? Can you handle employee and customer complaints? Managing a business involves managing your time, other peoples
time, your customers complaints, and your suppliers, as well as your banker, attorney, accountant, and financial planner.
Are you flexible? Can you adapt and grow as your business grows? Are you innovative enough to contribute to the expansion of
the company? What will customers want next year? Where will the market be in 5 years?
Analyze yourself carefully to make sure you are prepared for the challenges. Not everyone is made to own a business. Not
everyone has all the skills needed to operate a business. Identify the skills and strengths you have and determine if you can hire
another person or several individuals to make up for your weaknesses.
Where Is Your Market?
The marketing process includes a range of activities intended to identify and satisfy the desires of consumers while earning a
profit for the business. These activities include identifying customer needs, developing products and services to meet those
needs, establishing promotional programs and pricing for the products and services, and implementing a system of distribution to
the customers. It is essential to identify and understand the market, know who the competition is, and develop a market niche.
Remember, grow what sells, not what you are fond of.
Selling plants directly to consumers in a retail business is different from selling plants wholesale to garden centers or other retail
businesses. To determine if a consumer market is large enough, conduct a demographic study—a study of the characteristics of a
particular area. This should help you assess whether a greenhouse business is feasible. Characteristics that should be of interest
are population, projected population growth, age distribution, income levels, age of community, number and size of residential
areas, types of housing and lot sizes, trade areas, gross retail sales, unemployment rate, and major employers. Some important
questions to consider are the following:
Do enough people live or shop in the market area you choose?
How much competition do you face?
Are a lot of other businesses already growing and selling the products you would like to produce?
If you will sell plants to a wholesale market:
Are there distributors or wholesalers who could purchase your plants?
Can you sell directly to retailers in your market area?
Are there enough retailers who could purchase your products?
What advantages, such as higher quality plant material, a broader product mix, or improved services, can you offer retailers to
encourage them to purchase plants from you rather than from their current suppliers?
You need to understand the market, how it looks today, and how it will look in 5 years before deciding to go into business. It may
be difficult to collect enough information about the market to make a decision. The local chamber of commerce may be able to offer
assistance. Ask the local library for additional information. The telephone book is an excellent resource when assessing the
competition. Take a little time to look for sources such as census reports, demographic studies, newspapers, and the World Wide
Web. Other very good information sources are real estate agencies and the county Extension office. Be creative to find as many
facts as possible to help you make decisions about the market.
Characteristics of the markets will have an impact on the type of marketing you choose. Plants can be marketed at wholesale,
retail, or, in some cases, mail order. Wholesale production greenhouses sell relatively large amounts of products to a small
number of accounts. They may sell to florists, independent garden centers, grocery stores, mass merchants, home centers,
landscape businesses, or grounds maintenance firms. Many wholesale greenhouses grow a wide range of products throughout
the year for daily, seasonal, or contract sales.
A retail greenhouse sells a relatively small amount of products to a large number of individual customers. This type of operation
generally requires high product quality, active marketing, and superior service to succeed. Many retail merchandisers do not grow
plants, but purchase all or most of their products from wholesale growers. The greenhouse serves to maintain plant health until
sold, not to increase plant size. Retail growers produce a variety of plants to sell from their own retail operations. Because it is
often disruptive to have customers selecting products in a production facility, the retail facility is often separate from the
production facility. The retail facility may be at the same or at a different location.
What Type of Business Will You Establish?
Another consideration in starting a greenhouse business is to decide how the business will be structured legally. Usually, the
business is structured in one of three ways: sole proprietorship, partnership, or corporation. Each legal structure has several
advantages and disadvantages. Consult an attorney and accountant to decide on the structure that best suits your needs.
Most entrepreneurs start in the sole proprietorship legal form of business. The primary advantage of this form of business is that
you, the sole proprietor, are responsible for the assets and liabilities of the business. You are the boss. You have complete
liability, and you are taxed personally for the profits of the business. However, your personal and business assets can be taken
away if the business has financial trouble and you owe creditors money.
A partnership, with one or more partners, is another type of business with some different advantages and disadvantages. A
partnership may have more resources and partners sharing the responsibility and the liabilities, but you have at least one other
individual that you can consult regarding business decisions. Some people find this a great advantage because one person may
be good at growing plants and the other may be good at operating a business. This interaction can work to the advantage of
both. Like the sole proprietor, all partners are liable for the business's assets and their own personal assets can be jeopardized if
the business has financial difficulty.
The corporation is the third form of business structure. Today, more greenhouse businesses are corporations because of the
advantages a corporation offers. Unlike the sole proprietorship and partnership, the corporation is only liable when financial
difficulties arise. Only the business assets can be taken if creditors demand payment. The primary disadvantage to a corporation
is that the business is taxed twice: one time on the profits the corporation earns and a second time when the owners of the
corporation receive personal income from that corporation.
Where in Your Market Will You Locate Your Business?
Location of the property in the market area will affect the success of the business, especially if it is a retail business. Study the
market to determine the best location. Real estate agents will tell you that the three most important considerations for a retail
business are (1) location, (2) location, and (3) location! For a wholesale business, access to the market is more important than
the markets (your customer) access to you. When considering where in the market area to locate a business, think about the
following.
Size and shape. The exact size and shape of the property will depend on what size business you are planning to start and the
layout of that business. However, a minimum of 3 acres is recommended. In general, property with more road frontage is more
expensive, but it is also more visible to customers. Plan for expansion. Is there enough room to grow in the next 5 years or so
until you can afford to purchase more property for the business?
Zoning regulations. Make sure the property is zoned for business. Check to see if zoning is likely to change in the near future or if
it has been disputed in the recent past. Are there any special restrictive clauses that may inhibit your expansion? Are there
regulations on the size or height of signs that can be used to promote your business?
Accessibility. The business should be close enough to major roads for delivery and transport trucks to have easy access. Are there
any weight limits or restrictions on large trucks? For a retail greenhouse, locate the business so customers can see it from at least
200 feet and can get to the business easily and safely. Plant shopping is often done on impulse. If customers have to cross major
barriers or make a special effort to get to your business, chances are they won't.
Labor availability. Operating a greenhouse business is labor intensive and obtaining experienced, dependable labor can be
troublesome. Readily available labor and support facilities should be within 20 minutes drive of the greenhouse site. Is there a
good source of skilled labor in the area, such as a high school program with horticulture students, a university, college, or
technical school? Also, extra unskilled help will be needed during peak business times. Good sources of extra, part-time help are
high school students or older, retired adults. Labor should be available at a price you can afford.
Water quality and availability. Is city water available or will you have to dig a well? If you dig a well, how much water is available
and how long will it last? Many greenhouses require about 6 acrefeet of water per year for every acre of greenhouse production
area. Regardless of the source, have a water quality test performed. This is an inexpensive, easy procedure that may save a lot
of money in the future.
Private labs or your county Extension agent can help take the water sample and have it analyzed. Check the level of soluble salts
and bicarbonates. Low soluble salts, a level below 0.75 mmhos/cm, is best because fertilizer is often added to the water during
irrigation. When present in excess amounts, some salts are toxic to plants. Water bicarbonate level is important in plant
production. A bicarbonate level of less than 100 ppm (parts per million) is recommended for growing most plants.
You will also need a plan for water collection and a plan for water runoff from your greenhouse.
Utilities. How many are available, and what are the connection fees? You will need electricity and, depending on other equipment
and needs, you may need gas, water, or sewer services connected. Check with each supplier to determine costs and to anticipate
any difficulties they might have in supplying services.
Taxes. What is the tax rate on the property? Are taxes likely to increase substantially in the future forcing you to move the
business elsewhere?
Local building codes. What codes will affect which buildings you construct and where on the property you locate them?
Neighboring businesses. What affect will other businesses have on traffic flow of customers into and out of your business?
Natural slope and drainage of the land. Grading land can be very expensive. Greenhouse structures should be located on a slope
of 5 percent or less. Avoid locating a greenhouse on a flood plain, in a frost pocket, or on a hilltop where heating costs will be
high. Avoid an area where nearby structures or trees will cast shadows on the greenhouses.
Resale value. Someday it may be necessary to sell the property, for good or bad reasons, so have an estimate of its resale value
in the future.
Your Business Layout
In a wholesale production greenhouse, the primary factor to consider in arranging buildings and equipment is materials flow and
how it impacts labor utilization and future expansion. How will materials come into the facility (delivery and unloading), be stored
until needed, and be moved through the production process? How will products move out for packaging and be delivered to
customers? Labor is often the single largest expense in a greenhouse business, therefore, materials movement and handling
should be arranged to minimize the labor required. One possible arrangement is shown in Figure 1.
Materials flow is also important in a retail operation, but customer movement and access are also critical. How will products move
from delivery trucks to the display area, from the display area to the checkout register, and from checkout to the customers
vehicle?
What type of structures or areas do you need to start the business? A production facility and several other areas might be useful.
Some examples of specific structures and areas to keep in mind when considering the construction of a business are the
following: greenhouses, shade houses, work area, soil mixing area, storage buildings, pesticide room, roadways (large enough
for trucks), parking facilities, sales room, offices, landscaped area (display garden), break room/kitchen, rest rooms, cashier
location, loading dock, and shipping area. The sizes of each of these specific areas depend on plans and goals for your individual
business.
Greenhouse Styles
Generally, there are two styles of greenhouse layout commonly used for new businesses: detached or freestanding houses or
ridge and furrow or gutter connected houses (Figure 2). Detached greenhouses stand independently and may be constructed
using different greenhouse types (gable, Quonset, etc.). Access from the work area to the greenhouses is often through a
central, covered corridor or uncovered aisle. This layout style is common for small growers who are starting with 10,000 square
feet or less, but who plan to add houses as the business grows. This style has advantages and disadvantages. Each house can
be controlled by its own heating/cooling system to accommodate crops requiring widely different environments. Efficient
movement of people and materials, however, can be a problem, especially in inclement weather.
Ridge and furrow greenhouses are connected at the eave by a common gutter. Different types of greenhouse construction can be
used for a given row of connected houses. Internal walls may separate individual greenhouse sections where crops require
different environments or internal walls may be absent where large, single crops are to be grown. Some advantages of the ridge
and furrow style are lower construction costs compared to detached houses, especially for future expansion, lower heating costs
per unit compared to detached houses, and more efficient movement of people and materials.
Greenhouse Types
The most common greenhouse construction for most new businesses is the Quonset type (Figure 3). These houses are
constructed with arched rafters covered with one or two layers of flexible plastic, usually polyethylene. One disadvantage of
polyethylene is that it is subject to ultraviolet light degradation and must be replaced every 2 to 3 years. The cost of construction
for detached houses is lower than the cost for other greenhouse types, usually $2.75 to $3.25 per square foot excluding heating,
cooling, and benches. Many new businesses start with one or more houses that are 25 to 40 feet wide and 90 to 100 feet long.
However, this type of construction can be applied to either the detached or the ridge and furrow styles.
Many greenhouse construction companies offer packages for constructing Quonset greenhouses. These commonly come with
either steel or aluminum bows and the manufacturer specifies the bow spacing depending on the structural strength of the bow
material. However, before purchasing, select the frame based on load-bearing requirements. This will be determined by whether
or not the structure will support equipment or crops. Hanging the heating system, irrigation equipment, or hanging baskets from
the framing will increase the load-bearing requirement. The end walls are often constructed of wood or metal framing covered in
polyethylene or rigid plastic with aluminum doors for access. The side walls are often wood or metal with special fasteners for
holding the polyethylene in place. The foundation for a Quonset greenhouse is usually a concrete footing poured at intervals
dictated by the bow spacing.
Polyethylene manufactured for greenhouse application comes in 20- to 50-foot widths, 1 to 8 millimeters thick. It costs $0.12 to
$0.18 per square foot. Two layers of polyethylene are frequently applied to greenhouses to reduce heating demand. Double-layer
polyethylene houses generally cost 30 to 40 percent less to heat than do single layer houses. The two layers are kept air-inflated
using a 100 to 150 ft.3/min. squirrel cage blower mounted to the inside plastic layer. Purchase 4-mil plastic for the inside layer
and 4- or 6-mil plastic for the outside. Use 6-mil polyethylene for single layer applications. Polyethylene can be installed on wood
portions of a greenhouse by nailing wood batten strips over the film into the foundation boards and end walls. However, because
polyethylene will require replacing frequently, investing in special fasteners will make the job easier. Fastening systems are
available for single- or double-layer applications.
A second commonly applied greenhouse type is the even span, gable roof (Figure 3). This type of construction is appropriate
where rigid glazing materials will be used such as glass or rigid plastics. The cost of construction for glass-covered, detached-
style houses is higher than for Quonset types, usually $5.50 to $7.50 per square foot excluding heating, cooling, and benches.
However, these structures are more permanent and require less maintenance. Gable construction with rigid glazing is a good
choice when plans are long-term and the business is well capitalized. This type of construction can also be applied to either the
detached or the ridge and furrow styles.
Gable houses use galvanized steel, aluminum, or a combination of the two materials for constructing the frame. The weight of
glazing material, the weight of equipment attached to the frame, snow and wind loads, and the width of the greenhouse will
have an impact on the type and size of materials chosen, size and spacing of support posts, and the design and construction of
trusses. Glass is very heavy and requires strong support while rigid plastics are lighter requiring less support. Trusses and
support posts may be spaced 6, 10, or 12 feet apart depending on load requirements while roof and side bars are spaced
according to the width of the glazing material used. In recent years, eave heights have increased to 12 to 15 feet or higher in
southern greenhouse construction because taller houses ventilate better and stay cooler. Gable houses, especially those covered
with glass, should have a strong, concrete, or concrete block foundation that extends below the frost line according to building
codes.
Glass is the traditional greenhouse covering against which all other materials are judged. Originally, glass panes for greenhouses
were 18 by 16 inches, but larger sizes are becoming more common. Actually, larger panes are less fragile than are smaller panes.
Many greenhouses are covered with double-strength float glass (1.8-inch thick) costing $0.85 to $2.00 per square foot. Large,
glass panes and tempered glass may cost $3.00 to $7.00 per square foot.
Fiberglass reinforced panels (FRP) are rigid plastic panels made from acrylic or polycarbonate that come in large, corrugated or flat
sheets. FRP panels are available in 24- to 57-inch widths and up to 24-foot lengths. These materials are durable, retain heat
better than glass, and are lightweight (less structural support needed). Light transmission may be better than glass simply
because less structural support is needed, therefore, fewer shadows are created. The cost of FRP panels range from $1.00 to
$1.25 per square foot depending on the guaranteed life-span of the material.
Double-layer structured panels (DSP) are made from acrylic or polycarbonate and are constructed of two layers of plastic held
apart by ribs spaced 1 to 2 inches apart. The double-layer construction increases structural strength and heat retention, but
decreases light transmission compared to singlelayer materials. Panels may be 4 feet wide and up to 39 feet long. DSP made with
polycarbonate costs $1.75 to $2.50 per square foot while those made with acrylic costs $2.00 to $3.50 per square foot.
Floors and Walks
The type of floor for a greenhouse will depend on the type of production (pots or flats on the floor or on benches), available
capital, and soil drainage. Bare ground should be avoided because of potential insect, disease, and weed problems and the
presence of a muddy growing surface. Weed mat overlain with 4 inches of ¾-inch crushed stone or pea gravel will help control
weeds and provide a porous medium through which water can drain. Areas under benches can be treated the same way. If a
solid concrete floor is desired or necessary, install drainage basins and slope the floor toward the drains. Concrete aisles are
preferable where carts and wheeled equipment will be used. Walkways can be 2 to 3 feet wide in a small greenhouse. Adjust the
width of walks for wheeled equipment. Larger greenhouses often have 2- to 3-foot secondary aisles and 4- to 6-foot or wider
main aisles.
Benches
Benches may be constructed from a variety of materials and arranged in many different ways. Careful planning can result in 70 to
80 percent of floor area devoted to crops with fixed benches and up to 90 percent utilization with rolling or movable benches.
Rolling benches are designed to open an 18- to 24-inch aisle of work space at any location along a row of benches.
Supports for benches should be strong enough to hold a large number of plants and the largest container size anticipated. Wood,
metal pipe, or concrete blocks have been used as bench supports. The bench surface should be strong enough to support plants
without sagging, but open to provide water drainage and air movement. Spruce or redwood lath and 1-inch square, 14-gauge
welded-wire fabric or expanded steel mesh make a strong, long lasting, open bench top. Bench height should be 32 to 36 inches
and width should be 3 feet if against a wall or up to 6 feet if accessible from both sides. Benches can be purchased from a
manufacturer in a variety of sizes and construction types.
Ventilation
The purposes of ventilation are to exchange carbon dioxide and oxygen, to remove hot air, and to lower relative humidity. Forced-
air ventilation relies on electric fans controlled by a thermostat and a louvered intake vent. Fans pull cool air into the greenhouse
from the outside through an intake vent and warm, inside air is pushed out. Fans should be mounted in a waterproof housing
with exterior, air-activated louvers to protect electrical components from inclement weather and to keep cold air out during the
winter. It is important to install a screen over the inside of fans to prevent injury. There should be a distance equal to at least 1.5
times the fan diameter between the fans and adjacent structures. The intake vent on the wall opposite the fans can have an air-
activated or motorized louver. Fan capacity should be large enough to exchange the air in a greenhouse at least once per minute.
Recommendations for warm climates call for a fan capacity to remove 12 to 17 cubic feet of air per minute per square foot of floor
area.
Natural ventilation has made a comeback in the South in recent years in the form of retractable-roof greenhouses and Quonset
houses with roll-up side walls. Retractable-roof greenhouses come in a variety of types while roll-up side walls on Quonset
houses are relatively simple. In both cases, the idea is to move as much of the greenhouse structure out of the way as possible
to expose crops to natural conditions during warm weather.
Cooling
One of the best ways to cool a greenhouse in the summer is to reduce light intensity. How much reduction to provide depends on
the heat load in the greenhouse and the light requirements of the crops grown. Greenhouse whitewash and shade cloth are
popular choices. Greenhouse whitewash is a special kind of latex paint that is diluted in water and sprayed on the covering
surface. This material is designed to be applied in the spring and gradually degrade by the action of rain and sun so that little
remains by fall. Shade cloth is a black, green, or white woven fabric of polypropylene that is applied over the outside of the
covering. Shade cloth can be purchased with various weave densities that result in 20 to 80 percent light reduction. For many
greenhouse applications, 30 to 50 percent light reduction should be sufficient.
Evaporative cooling relies on air passing through a porous pad saturated with water. The evaporating water removes heat from
the greenhouse. Fan-and-pad systems consist of a cellulose pad the length of one wall and at least 2 feet tall with water
supplied to keep the pad wet during operation. Fans along the opposite wall draw outside air through the pads. Fan-and-pad
systems cool more efficiently when the relative humidity is low, a condition that is infrequent in Southeastern summers. However,
a 5 to 10 degree reduction over the outside temperature can be achieved with a well-designed system.
Heating
Two popular heating systems for greenhouses are forced-air unit heaters that burn propane or natural gas and hot water or
steam central boilers that burn fuel grade oil. Unit heaters cost less in initial investment ($.30 to $.50 per square foot) than
central boilers ($1.00 to $2.50 per square foot), but cost more to operate ($1.00 per square foot versus $.60 per square foot).
Unit heaters are easier to install and require less maintenance than central boilers require, but even heat distribution can be a
problem. Central boilers provide even heat and combustion takes place away from the greenhouse, but installation can be time
consuming. Generally, unit heaters are more appropriate for small greenhouse ranges and central boilers for larger ranges.
Unit heaters burn gas in a firebox and heated air rises through the inside of a thin-walled heat exchanger on its way to the
exhaust chimney. A fan draws air in from the greenhouse, across the outside of the heat exchanger and into the greenhouse.
Thus, most of the heat is removed from the exhaust before it exits the structure. The exhaust chimney must be sufficiently tall to
maintain an upward draft and extend above the greenhouse roof. An 8- to 12-foot chimney is usually sufficient. Open flame
heaters must be vented to the outside and be provided a fresh air supply for complete combustion. Fresh air must be provided by
an unobstructed chimney to avoid carbon dioxide buildup and production of ethylene, both detrimental to plants.
Two warm-air distribution systems are popular for unit heaters: convection tubes and horizontal airflow. A convection tube is a
polyethylene tube connected to the air outlet of the unit heater, running the length of the greenhouse and sealed at the other
end. Warm air is distributed in the greenhouse through rows of 2- to 3-inch diameter holes on each side of the tube. Horizontal
airflow relies on a number of horizontally mounted fans 2 to 3 feet above the plants that circulate heat throughout the house.
This system as well as convection tubes may also be used at times when heating is not required, especially at night, to reduce
relative humidity and discourage diseases.
Central boilers burn fuel in a fire box to heat water to 180 degrees F or to steam in a heat exchanger. Exhaust smoke passes
through a flue to a chimney that vents exhaust to the outside. The heated water or steam is delivered to the greenhouse to
exchange heat with the air through pipe coils, unit heaters, or a combination of both.
Climate Control
Traditionally, the operation of heating, ventilating, and cooling equipment has been controlled by thermostats at plant level
located close to the center of the greenhouse. This system is still used effectively in small operations, especially those with
detached greenhouses. For accurate control, thermostats should be shaded from direct sunlight, preferably by mounting them in
a plastic or wood box ventilated by a small blower. Thermostats have the advantages of being simple, inexpensive, and easy to
install, but may be inaccurate and lack coordination with environmental control equipment.
Step controllers and dedicated microprocessors overcome the limitations of thermostats by providing more complex staging of
heating and cooling systems and by coordinating the activities of heating, cooling, and ventilating equipment. These units
generally cost from $800 to $2,500. Greenhouse environmental control computers add additional levels of control over
greenhouse equipment along with weather sensing, environmental data logging and plotting, and other functions.
Irrigation Equipment
Hand irrigation using a hose, water breaker, and wand is still one of the most widely used methods of watering crops for small
greenhouse operations. However, as the business grows, the cost in labor, the skill required to water effectively, and the logistics
of hand watering large crops become prohibitive. Many attempts have been made to utilize impact sprinkles to water greenhouse
crops, often with poor results. System design is critical to prevent wet and dry spots, excessive foliar wetting, and large volumes
of runoff. Boom irrigation is probably one of the most effective and uniform methods of overhead irrigation. Water is delivered
through fan-pattern emitters mounted on a rigid boom that travels back and forth across the greenhouse. Booms limit runoff
when used correctly, but crops must be reasonably uniform in size, age, and water requirement under a single unit to be
applicable. The cost of installing booms is probably prohibitive for most new greenhouse businesses.
Drip emitter watering is probably the most common type of automatic watering system. Water is delivered to each pot through a
small-diameter, polyethylene microtube held on the medium surface by a lead or plastic weight to keep the tube in the pot.
Multiple microtubes on a bench are supplied with water from a black polyethylene (usually ¾") header running down the center of
the bench and connected to a water main. Each bench may be turned on or off by a hand valve or electric water solenoid valve
installed where the header connects to the water main. Many benches or whole greenhouses can be divided into watering zones,
the size of which depends on the capacity of the water supply. Watering can be controlled by devices as simple as on/off switches
or as complex as an environmental control computer. Drip emitters deliver water directly to the medium surface at low volume
and, therefore, do not wet the foliage. However, their application is usually limited to 4- to 10-inch pots and crops must be
reasonably uniform in size, age, and water requirement under a single zone to be applicable.
Subirrigation involves supplying water by flooding to the drainage holes in the bottom of the pots. The water is absorbed by
capillary action upward through the potting medium. Capillary mats, gutter benches, flood benches, and flood floors are systems
that vary in complexity and cost. All share the advantages of being adaptable to a wide range of container sizes and have the
potential for recycling runoff water. However, monitoring nutrients, pH, soluble salts, and contaminants in closed systems requires
good management skills.
Fertilizer Injection
A fertilizer injector is a mechanical device that introduces soluble fertilizer dissolved in water (stock solution) into the water
pipeline for delivery to the plants. A wide variety of injector devices are available on the market with a range of capacities (gallons
per minute) and costs. Inexpensive units such as Hozon or Syfonex connect between a faucet and hose and suction fertilizer
concentrate from a bucket into the water line using the Venturi principle. These units have a fixed injection ratio delivering 1
gallon of stock in 16 gallons of water (1:16). These units are only useful for the smallest applications because the injection ratio
can vary with changes in water pressure and large volumes of fertilizer concentrate are required. Positive displacement units such
as Anderson, Dosmatic, Dosatron, Gewa, and Smith injectors cost more than Venturi types cost, but are much more accurate and
reliable and offer a wider range of injection ratios.
When choosing a fertilizer injector, match the correct model with the maximum water flow rate that the unit will be expected to
handle. The range of injection ratios available on a particular model will influence maximum daily water output and reasonable
stock tank size. Some applications require use of chemicals other than fertilizers, have need for separate injection heads for
incompatible chemicals, or present the problem of portable versus fixed installation. Consult the manufacturer to determine the
correct model for a particular application.
Crop Selection
What crops should you grow? How many should you grow? What does the customer want? Do your customers want annuals,
perennials, flowering plants, herbs, or ornamental grasses? What container sizes do they prefer? How many can they use? You
may have some idea about the types of plants you cannot find in the market. You may even have some idea about the types of
plants that may be in demand in the next year or two. There is no easy way to determine which crops to grow and how many, but
demand in the market should drive production. Only produce what you can grow at a cost low enough and sell at a price high
enough to make a profit.
The critical side of profitability is cost of production. The level of competition often sets the selling price. Know your cost of
production for each crop and select crops and production methods for profitability. The difference between cost and price—the
margin—must be large enough to operate the company, pay yourself a wage, justify the risk of being in business, and provide a
return on your investment. Grow the best quality product demanded by the market you are in. Do not sacrifice quality to lower
cost. Without quality, you will not survive in the market.
To get an idea of current trends in crops, read industry trade magazines such as Greenhouse Grower, Greenhouse Manager, and
GrowerTalks. Read homeowner and homemaker magazines such as Southern Living, Better Homes and Gardens, Woman's Day,
House Beautiful, and Family Circle. See what the industry is talking about in terms of new plants that may have desirable
characteristics such as good heat tolerance and disease resistance. See what customers are doing now by reading the
publications they read.
First consider producing the most popular varieties and then gradually introduce newer varieties or plants to customers. Add 10
to 30 percent new plant varieties each year. Remember that it is difficult for people to change anything, including the type of
plants they are accustomed to buying. The only way they will change is if you educate them. You will be looked to as the expert
for information and advice. Gather that information yourself and share it with customers. Plant the varieties you grow in a display
garden for you and your customers to evaluate. Visit other gardens to see how well plants perform under similar conditions. Visit
trial gardens to learn about new varieties and plan to include them in your production schedule in the future.
Another factor in selecting a crop to grow is deciding how to grow it. Crops can be started from seeds, plugs, or cuttings. The
propagation decision depends on the species, cost, scheduling and timing of the crop, available facilities and equipment, and
availability of seeds, plugs, or cuttings. Determine the cost of production using several different propagation methods and see
which is the most profitable. Your level of experience may also influence the best method to start a crop. For example, if you have
never grown bedding plants, starting with plugs will reduce the risk associated with germination, but it will increase the cost.
Eventually, you may want to produce plugs for your business to use or perhaps to sell to other businesses.
Complying With Alabama State Laws
Greenhouses need to be licensed by the state of Alabama to conduct business. Plants that are shipped out-of-state must comply
with any insect and disease quarantine regulations. For information on complying with state regulations, contact the Plant
Industry Section of the Alabama Department of Agriculture and Industries, P.O. Box 3336, Montgomery, AL 36193. Your local
Extension agent can also assist in contacting your county�fs plant industry inspector, who will inspect your crops and provide
additional information.
Keeping Good Records
Unfortunately, record keeping is an area of business that many new, small business managers neglect. However, keeping good
records is a simple task and in the long run can save time and money. A computer can make the task of record keeping easier.
Some records you will want to keep are the following:
Business records. Keep record of cash flow, inventory, income statements, and balance sheets. Any general accounting records
can be kept on a computer and will be available to assist in planning for growth of the business.
Employee records. A record of hiring dates, hours worked, rewards, and reprimands needs to be kept. Tracking hours worked by
employees can help in planning for seasonal needs and in seeing where the greatest labor needs are.
Crop scheduling. It is useful to record fertilizer applications on crops, planting dates, finishing dates, and other cultural practices
for planning future production and as a cultural reference. Legally, you must keep a record of pesticide spray dates, rates, and
chemicals used.
Customer records. Keep a record of names, addresses, and telephone numbers to contact past customers directly.
Canada: Nature Fresh Farms completes 32 acre greenhouse expansion
1,500,000 cartons of Beefsteak tomatoes are expected to be harvested in the 2012 Season from the new 32
acre high tech greenhouse facility. The new facility, which has been dedicated to beefsteak tomatoes, was
planted November 30th and the first harvest is expected mid-February 2012.
Nature Fresh Farms current acreage exceeds 128 acres and an additional 96 acre expansion is set to begin
2012. When completed, Nature Fresh Farms will exceed 225 acres of a broad mix of production commodities
and varieties.
Peter Quiring, President of the company, stated “We are looking to bring more variety in our offerings to our
customers and this new facility along with our sweet colored bell peppers, cluster tomatoes, specialty
tomatoes, seedless cucumbers, baby seedless cucumbers and eggplant, makes us a full line supplier of
greenhouse produce.”
Nature Fresh Farms is currently the largest greenhouse grower of sweet colored bell pepper in North America,
and the largest greenhouse grower in Canada. Nature Fresh Farms products are marketed and sold through
Nature Fresh Farms Sales Inc. Brands include Nature Fresh & Great Lakes Fresh branded Peppers, TOV’s,
Beefsteak, Seedless Cukes, Baby Eggplant, Amorosa branded Cocktail tomatoes, KISS brand grape
tomatoes, Heritage brand tomatoes, Natures Flavors mixed colors and flavors bite size tomatoes.
1,500,000 cartons of Beefsteak tomatoes are expected to be harvested in the 2012 Season from the new 32
acre high tech greenhouse facility. The new facility, which has been dedicated to beefsteak tomatoes, was
planted November 30th and the first harvest is expected mid-February 2012.
Nature Fresh Farms current acreage exceeds 128 acres and an additional 96 acre expansion is set to begin
2012. When completed, Nature Fresh Farms will exceed 225 acres of a broad mix of production commodities
and varieties.
Peter Quiring, President of the company, stated “We are looking to bring more variety in our offerings to our
customers and this new facility along with our sweet colored bell peppers, cluster tomatoes, specialty
tomatoes, seedless cucumbers, baby seedless cucumbers and eggplant, makes us a full line supplier of
greenhouse produce.”
Nature Fresh Farms is currently the largest greenhouse grower of sweet colored bell pepper in North America,
and the largest greenhouse grower in Canada. Nature Fresh Farms products are marketed and sold through
Nature Fresh Farms Sales Inc. Brands include Nature Fresh & Great Lakes Fresh branded Peppers, TOV’s,
Beefsteak, Seedless Cukes, Baby Eggplant, Amorosa branded Cocktail tomatoes, KISS brand grape
tomatoes, Heritage brand tomatoes, Natures Flavors mixed colors and flavors bite size tomatoes.
GreenEarth Co. Recommends:
Overview of Cravo Retractable Roof Greenhouses/Shadehouses
Over the last 29 years, Cravo has developed a wide range of A Frame and Flat retractable roof houses
and coverings to suit your crop, climate and budget. Cravo retractable roof houses are in operation in
cold climates with heavy snowloads, in the hot, dry arid conditions of the desert, and the hot, humid and
windy conditions of the tropics. In fact, Cravo houses have been hit by 7 hurricanes, without loss of any
structure or roof covering. You can be assured of a long trouble free operation since drive systems are
mostly made of stainless steel and aluminum, and the retractable white and clear roof coverings have
proven useful lives of 8 to 12 years depending on climate, use and crops being grown. Cravo roofs also
require minimal electricity since one 2hp motor can power approximately 1 hectare of flat roof and .5
hectare of A frame roofs.
Over the last 29 years, Cravo has developed a wide range of A Frame and Flat retractable roof houses
and coverings to suit your crop, climate and budget. Cravo retractable roof houses are in operation in
cold climates with heavy snowloads, in the hot, dry arid conditions of the desert, and the hot, humid and
windy conditions of the tropics. In fact, Cravo houses have been hit by 7 hurricanes, without loss of any
structure or roof covering. You can be assured of a long trouble free operation since drive systems are
mostly made of stainless steel and aluminum, and the retractable white and clear roof coverings have
proven useful lives of 8 to 12 years depending on climate, use and crops being grown. Cravo roofs also
require minimal electricity since one 2hp motor can power approximately 1 hectare of flat roof and .5
hectare of A frame roofs.
US: Greenhouse growing offers safety advantages
When consumers think about where their produce comes from, they usually imagine acres of open fields. But for a
significant portion of the tomato market, the product consumers buy isn't even grown in soil.
These are greenhouse operations which grow their tomatoes in an enclosed environment in order to exert a fine
degree of control over the growing process. Such a system can give greenhouse growers many advantages.
“In our greenhouse environment, we're able to control most of the variables involved with growing,” says Helen
Aquino of Village Farms.
Village Farms is the leading vegetable greenhouse producer in North America. It operates 232 acres of greenhouse
facilities. Those facilities, according to Aquino, give Village Farms some advantages when it comes to food safety.
“We're able to control most of the variables involved with growing, and that equates to higher food safety,” she says.
They also grow their tomatoes hydroponically, which means that there's less threat from microorganisms which might
be in the soil.
Pure Hothouse Foods also grows their tomatoes hydroponically in a greenhouse, and Sandra Dick, Marketing
Coordinator for Pure Hothouse, also believes that the lack of soil in the growing process mitigates certain risks. She
notes that growing hydroponically means they can avoid contamination through the soil of certain pathogens, like
listeria.
She also agrees that greenhouses afford an exceptional level of control.
“We control the application of everything that interacts with our crops,” she says, “so there is no danger of animals
wandering in, or of pesticide drift, and there is no access to foreign contaminants.”
However, such a high degree of precision comes with high investment costs to set up such a controlled environment.
It's that aspect of greenhouse growing which might not make it the best option for all growers.
“The controlled environment greenhouse growing we do is a high-tech endeavor,” says Aquino, “and there are high
start-up costs associated with developing a greenhouse of this nature.
But she also touts the efficiencies that come with greenhouse growing as something that makes the endeavor worth
undertaking. Such efficiencies are achieved by recycling water and planting more intensely, thus getting higher yields
per acre. Additionally, the controlled environment of a greenhouse allows the growing of tomatoes 365 days out of the
year, further boosting productivity.
Thus, as Aquino points out, despite the high initial cost, for some growers, it makes sense.
“For us,” she says, “it's worth the investment.”
For more information, please visit: www.villagefarms.com
When consumers think about where their produce comes from, they usually imagine acres of open fields. But for a
significant portion of the tomato market, the product consumers buy isn't even grown in soil.
These are greenhouse operations which grow their tomatoes in an enclosed environment in order to exert a fine
degree of control over the growing process. Such a system can give greenhouse growers many advantages.
“In our greenhouse environment, we're able to control most of the variables involved with growing,” says Helen
Aquino of Village Farms.
Village Farms is the leading vegetable greenhouse producer in North America. It operates 232 acres of greenhouse
facilities. Those facilities, according to Aquino, give Village Farms some advantages when it comes to food safety.
“We're able to control most of the variables involved with growing, and that equates to higher food safety,” she says.
They also grow their tomatoes hydroponically, which means that there's less threat from microorganisms which might
be in the soil.
Pure Hothouse Foods also grows their tomatoes hydroponically in a greenhouse, and Sandra Dick, Marketing
Coordinator for Pure Hothouse, also believes that the lack of soil in the growing process mitigates certain risks. She
notes that growing hydroponically means they can avoid contamination through the soil of certain pathogens, like
listeria.
She also agrees that greenhouses afford an exceptional level of control.
“We control the application of everything that interacts with our crops,” she says, “so there is no danger of animals
wandering in, or of pesticide drift, and there is no access to foreign contaminants.”
However, such a high degree of precision comes with high investment costs to set up such a controlled environment.
It's that aspect of greenhouse growing which might not make it the best option for all growers.
“The controlled environment greenhouse growing we do is a high-tech endeavor,” says Aquino, “and there are high
start-up costs associated with developing a greenhouse of this nature.
But she also touts the efficiencies that come with greenhouse growing as something that makes the endeavor worth
undertaking. Such efficiencies are achieved by recycling water and planting more intensely, thus getting higher yields
per acre. Additionally, the controlled environment of a greenhouse allows the growing of tomatoes 365 days out of the
year, further boosting productivity.
Thus, as Aquino points out, despite the high initial cost, for some growers, it makes sense.
“For us,” she says, “it's worth the investment.”
For more information, please visit: www.villagefarms.com
Strong growth predicted
US: Organic farming takes root in Arizona
For just over a year, Alegria Hayes and Lyle Ford have been growing micro greens and cacao organically on five acres
of land in Sonoita, Ariz. Hayes started growing the plants after moving from New York City to the desert, where she
said she couldn't find the type of natural, raw foods that make up 100 percent of her vegan diet. At the urging of her
partner, she later expanded her own private garden to what is now known as Awaken Organics, run out of a 10-by-
20-foot greenhouse. "We're a very small operation, we produce 60 to 80 pounds a week," said Hayes, who is
working to get her farm certified as organic. Small or not, Hayes and Ford are part of a growing move toward organic
farming in Arizona, where the number of certified organic farms nearly tripled, from 26 in 2006 to 77 in 2008,
according to the most recent numbers from the U.S. Department of Agriculture.
The state increase mirrors the exponential growth of organic farms across the nation, where the Agriculture
Department says such farms jumped from 40 in 1997 to more than 12,941 in 2008. And the trend is expected to
continue, with another tripling of organic farms between now and 2015, according to a report by the Organic Farming
Research Foundation. Foundation spokeswoman Denise Ryan said that recent changes in eating habits of Generation
X have fueled the demand for certified organic produce and products. She attributes that increased demand to the
public perception that healthy eating will improve overall well-being. "I think we have a raised consciousness in this
country and never before has health been more imperative," Ryan said. "Organic farming provides a healthier
alternative that is manifested in human health and economic health."
Even with its newfound popularity, however, certified organic farms still accounted for only 13,742 acres of the 26.1
million farm acres in the state in 2007 - about 0.05 percent of the total, according the Agriculture Department
statistics. The organic acreage in the state doubled in 2008, to just over one-tenth of one percent. Arizona Farm
Bureau spokeswoman Julie Murphree said she has noticed the increase and expects the trend to continue. She
stressed, however, that standard farming and certified organic practices are both "extremely valuable, extremely
healthy and extremely necessary in the food continuum." Murphree defines the "food continuum" as the range in
types of farms. "If we don't embrace the entire food continuum we will not be able to produce the abundant and
nutritious agriculture in Arizona that we do today," Murphree said.
Hayes' farm is not officially certified organic, but she is working toward it. The process to take her farm from the
current certification of naturally grown to the next step, certified organic, requires her to keep up with paperwork and
open her farm to peers who serve as inspectors. Though some may be overwhelmed by the amount of paperwork -
certified farmers have to log just about everything, from when each area was cleaned to what type of fertilizer was
used - Hayes says it makes sense and actually helps her and her partner manage a farm as newcomers. "We come
from the outside, we're not farmers for generations," Hayes said. Janice Smith said that although the certification
process is a "tremendous amount of paperwork," it is worth it because it keeps farmers accountable. "It's very worth
the effort, not just for yourself but for the consumers eating your food," said Smith. She and her husband, Byron, run
an organic farm three hours north of Sonoita, in Wilcox.
Several years ago, the Smiths were also getting their start in organic farming, like Hayes. Today, their Sunizona
Family Farms is run with the help of family and about 23 year-round, full-time employees. Sunizona has been an
Arizona certified organic farm since 2009. Of the 300 acres on the farm, only about 20 are used to grow seasonal
crops and another three acres are used for year-round fruit and vegetable production in greenhouses there. Smith
said that besides being held accountable by the certification board, Sunizona has an open-door policy that lets any
customer come in for a tour at anytime. Sunizona takes organic one step further, describing its operation as
"veganic," meaning farmers there do not use any animal products in the production of their crops. "We feel this is the
future of farming," Smith said. "We're living in a time … where people want to know who grows their food." For Hayes,
it's been hard work so far, but she said she's enjoying her new endeavor. She said being organic has been simple
because, "nature takes care of everything."
Source: ktar.com
Publication date: 12/14/2011
US: Organic farming takes root in Arizona
For just over a year, Alegria Hayes and Lyle Ford have been growing micro greens and cacao organically on five acres
of land in Sonoita, Ariz. Hayes started growing the plants after moving from New York City to the desert, where she
said she couldn't find the type of natural, raw foods that make up 100 percent of her vegan diet. At the urging of her
partner, she later expanded her own private garden to what is now known as Awaken Organics, run out of a 10-by-
20-foot greenhouse. "We're a very small operation, we produce 60 to 80 pounds a week," said Hayes, who is
working to get her farm certified as organic. Small or not, Hayes and Ford are part of a growing move toward organic
farming in Arizona, where the number of certified organic farms nearly tripled, from 26 in 2006 to 77 in 2008,
according to the most recent numbers from the U.S. Department of Agriculture.
The state increase mirrors the exponential growth of organic farms across the nation, where the Agriculture
Department says such farms jumped from 40 in 1997 to more than 12,941 in 2008. And the trend is expected to
continue, with another tripling of organic farms between now and 2015, according to a report by the Organic Farming
Research Foundation. Foundation spokeswoman Denise Ryan said that recent changes in eating habits of Generation
X have fueled the demand for certified organic produce and products. She attributes that increased demand to the
public perception that healthy eating will improve overall well-being. "I think we have a raised consciousness in this
country and never before has health been more imperative," Ryan said. "Organic farming provides a healthier
alternative that is manifested in human health and economic health."
Even with its newfound popularity, however, certified organic farms still accounted for only 13,742 acres of the 26.1
million farm acres in the state in 2007 - about 0.05 percent of the total, according the Agriculture Department
statistics. The organic acreage in the state doubled in 2008, to just over one-tenth of one percent. Arizona Farm
Bureau spokeswoman Julie Murphree said she has noticed the increase and expects the trend to continue. She
stressed, however, that standard farming and certified organic practices are both "extremely valuable, extremely
healthy and extremely necessary in the food continuum." Murphree defines the "food continuum" as the range in
types of farms. "If we don't embrace the entire food continuum we will not be able to produce the abundant and
nutritious agriculture in Arizona that we do today," Murphree said.
Hayes' farm is not officially certified organic, but she is working toward it. The process to take her farm from the
current certification of naturally grown to the next step, certified organic, requires her to keep up with paperwork and
open her farm to peers who serve as inspectors. Though some may be overwhelmed by the amount of paperwork -
certified farmers have to log just about everything, from when each area was cleaned to what type of fertilizer was
used - Hayes says it makes sense and actually helps her and her partner manage a farm as newcomers. "We come
from the outside, we're not farmers for generations," Hayes said. Janice Smith said that although the certification
process is a "tremendous amount of paperwork," it is worth it because it keeps farmers accountable. "It's very worth
the effort, not just for yourself but for the consumers eating your food," said Smith. She and her husband, Byron, run
an organic farm three hours north of Sonoita, in Wilcox.
Several years ago, the Smiths were also getting their start in organic farming, like Hayes. Today, their Sunizona
Family Farms is run with the help of family and about 23 year-round, full-time employees. Sunizona has been an
Arizona certified organic farm since 2009. Of the 300 acres on the farm, only about 20 are used to grow seasonal
crops and another three acres are used for year-round fruit and vegetable production in greenhouses there. Smith
said that besides being held accountable by the certification board, Sunizona has an open-door policy that lets any
customer come in for a tour at anytime. Sunizona takes organic one step further, describing its operation as
"veganic," meaning farmers there do not use any animal products in the production of their crops. "We feel this is the
future of farming," Smith said. "We're living in a time … where people want to know who grows their food." For Hayes,
it's been hard work so far, but she said she's enjoying her new endeavor. She said being organic has been simple
because, "nature takes care of everything."
Source: ktar.com
Publication date: 12/14/2011
FAQ - Horticultural Lighting
General lighting questions:
1.What is HID Lighting?
HID lighting stands for High Intensity Discharge, which is a special type of lighting that is much more intense (brighter) than other
types of lighting available. An HID lighting system consists of a ballast, reflector, socket and lamp (light bulb). The ballast acts like
the engine, converting and driving energy to illuminate the lamp. HID lighting options include High Pressure Sodium (HPS), Metal
Halide (MH), Mercury Vapor and Low Pressure Sodium. The two typically used for plant growth are HPS and MH systems.
2.What is Color Rendering Index (CRI), Color Temperature (K) and Lumen?
Color Rendering Index is a subjective measurement of how well a lamp source renders colors. A measurement of the degree of
color- shift an object undergoes when illuminated by a light source when compared to a reference source of comparable color
temperature. Incandescent light is assumed to have a CRI of around 100 so it will render all colors correctly. MH only has a CRI of
about 70, so only 70% of colors will be rendered correctly. HPS has a CRI of 22.
Color Temperature is not how hot the lamp is. Color temperature is the relative whiteness of a piece of tungsten steel heated to
that temperature in degrees Kelvin. HPS has a warm (red) color temperature of around 2700K as compared to MH at 4200K,
which has a cool (blue) color temperature.
What is important to remember about these two terms is that CRI readings, of two sources, can only be compared if their color
temperature is equal. You cannot compare the CRI of HPS (CRI=22) vs. Metal Halide (CRI=70) because the color temperatures are
dif erent (2200K vs. 4500K).
Lumen is a measurement of light output. It refers to the amount of light emitted by one candle that falls on one square foot of
surface located at a distance of one foot from the candle. Traditionally, lumens have been the benchmark of a lamps ability to
grow plants; meaning the brighter the lamp the better the plant. However, studies have shown that a broader color spectrum
lamp will perform much better than a lamp with high lumen output, especially when it comes to plant growth.
3.What is the difference between MH and HPS with regards to plant growth?
MH lamps provide more of the blue/green spectrum, which is ideal for leafy crops, and/or plants that are in a vegetative (actively
growing) stage. MH lamps provide a more natural appearance in color and are typically the choice for plants that have little to no
natural light available. HPS lamps provide more yellow/orange/red spectrum, which is ideal for most plants that are actively
fruiting and flowering. In addition, HPS lighting is the choice for growers looking to supplement natural sunlight. Ideally, the
horticulturalist will use MH to grow their plants and HPS to fruit and flower their plants.
4.What is the difference between HID and Fluorescent lighting with regards to plant growth?
Traditionally, fluorescent lighting was used for seedlings, cuttings and plants with low light-level requirements and HID was used
for established plants and plants with higher light-level requirements. Advances in fluorescent lighting technology, however, have
provided more options for horticulturists. T5 fluorescent lighting is the latest in plant growth lighting. T5’s high-light output
combined with its low heat and energy consumption makes it an ideal light source to grow a broader array of plants.
5.What are the benefits of using T5 fluorescent lighting for plant growth?
T5 lamps provide the ideal spectrum for plant growth. Photosynthesis rates peak at 435 nm and 680 nm. A 6500K T5 lamp has a
spectral distribution with relative intensity peaks at 435 nm and 615 nm. This equates to very little wasted light energy in terms
of plant growth. T5 lamps promote incredible health and vigor of seedlings and cuttings. Root development is superior relative to
other lighting sources. While T5 lighting is excellent for starting seeds and cuttings, it’s also able to produce enough light for full
term growth. Because of their minimal heat output, T5 lamps can be placed 6” - 8” above the plant canopy which maximizes
photosynthetic response. Unlike conventional fluorescent lamps, plants grown under T5 lamps do not have to be rotated to the
center of the lamp. T5’s slim diameter enables better photo-optic control of the emitted light, increasing efficiency in the form of
even light distribution.
Environmental Impacts of T5 (at a glance):
◦T5 lamps have a diameter of 5/8” – smaller is better when it comes to manufacturing, transportation and disposal.
◦Reduction in raw materials and components needed for manufacturing.
◦Reduction in lamp and fixture packaging materials due to relative size.
◦T5 are constructed of 40% less glass than T8.
◦T5 contain 30% less phosphor than T8.
◦T5 contain 3mg of mercury. 70% less than T8.
◦Longer lamp life means reduced maintenance cost and less going to the landfill.
.6.What are the major differences between HID ballasts and electronic ballasts?
Frequency output to the lamp and energy conversion from electricity to usable light are the biggest differences between HID
ballasts and electronic ballasts. HID ballasts produce a frequency of 60 Hz. Electronic ballasts vary from manufacturer to
manufacturer, but the frequency produced can be 400x that of an HID ballast. HID ballasts produce more heat than electronic
ballasts, thus making electronic ballasts more energy efficient. You will not, however, save money on your electric bill by using
electronic ballasts. HID lighting has been available for 60+ years, while electronic ballast (especially 400 watt and higher) is a
relatively new technology.
7.Are electronic ballasts more energy efficient?
Electronic ballasts are more efficient at converting electricity into usable light. Since your power bill is based on kilowatt-hours and
not efficiency, a 1000 watt electronic ballast will cost you about the same as a 1000 watt HID ballast to operate.
8.How much energy will my light use?
An average lighting system will increase your electricity cost about $8 to $20 per month. The exact amount depends on the
wattage of the system and the number of hours operated. To calculate your cost, multiply the bulb wattage X the number of
hours of operation and divide by 1000. This figure is the number of kilowatt-hours of electricity used. (Example: a 400 watt lamp
running for 18 hours will use 7.2 kilowatt-hours). Check your power bill for the cost of each kilowatt-hour. Then multiply the
number of kilowatt-hours used by the cost of a kilowatt-hour (K/hr) to figure the cost to run your light for that many hours.
9.Do I need special wiring in my house for my lighting system?
Lighting systems are available in a variety of voltages. The standard used by most gardeners is 120 volts / 60 Hz which plugs into
a standard wall outlet. Other voltages may require special circuits and receptacles. Always contact a licensed electrician if the light
you purchased has special voltage requirements and never exceed more than 75% of the rated ability of the fuse/breaker. (For
example: use no more than 15 amps on a 20-amp circuit.)
10.What voltages are available for HID and Fluorescent lights?
HID systems are available in 120 volt, 208 volt, 240 volt, 277 volt and 480 volt - All at 60 Hz. Fluorescent lighting varies, but most
are available from 100 volt to 277 volt and 50 Hz or 60 Hz.
11.Will I save on my electric bill if I run my system with 240 volts?
No. Electric companies base your electrical bill on Wattage, not Voltage or Current. While ballasts wired for 240 volt will draw less
current and run a little cooler than one wired for 120 volt, it will not save you money on your electric bill.
12.How often do I need to change my light bulb?
Most lamp manufacturers rate their lamps by “Average Life Hours” and usually claim 10,000 to 24,000 hours. These ratings are
based on when the lamp will completely fail to come on. They do not factor in loss of intensity or loss of color. HID lamps lose
intensity and color through normal use. This is OK if you are lighting a warehouse, but when it comes to plant growth, these
losses can mean wasted electricity and poor plant performance. Serious horticulturalists recommend that you replace your lamps
after 6000 hours of use. This equates to using your light 16 hours a day for one year.
13.How long should I run my lights?
This depends on the type of plants and whether you have natural sunlight available to your garden. As a general rule, when you
are in a vegetative stage of plant growth and you have no natural sunlight, run your lights 14-18 hours a day. If you have natural
sunlight, it will vary because the sunlight may or may not be direct. It will take a little experimenting to find the best length of time
to run your lights. If you are actively fruiting and flowering, the rule is to run your lights 12 hours a day if you have no natural light.
14.How high do I need to hang my lights above my plants?
The higher the wattage the further away you want the light to be from your plants due to the amount of heat. HID lighting will be
further away than a fluorescent fixture because of this. When mounting your lighting fixture take into account the type of plant
and how tall the plant will grow. You want to keep the light as close as you can, but not so close to burn the plant. A simple rule
is “if it is comfortable for the back of your hand, it will be a safe distance for your plants”. Doing a little research on the type of
plant and where it comes from will help in determining how much (or little) light your plants like. With fast growing plants, you may
need to check the hanging height on a regular basis as plants that get too close to the lamp will be severely burned.
15.How big of an area will my light cover?
The size of the garden area will determine the wattage you need. If we assume that the plants will get no sunlight, a 1000 watt
light will cover about 7 x 7 feet of growing area. A 600 watt will cover 6 x 6 feet, a 400 watt will cover 4 x 4 feet, and a 250 watt
will cover 3 x 3 feet. These sized areas would be considered the “Primary Growing” areas. These lights will light-up larger areas,
but plants placed outside of the Primary Growing area, will stretch and bend toward the light; a phenomenon called phototropism.
Keep these areas of coverage in mind when using multiple fixtures. The best results occur when the areas of coverage overlap.
16.Why do I need glass to get the ETL Listing on a Metal Halide light?
The inner arc tube of a Metal Halide lamp contains mercury. Eddison Testing Laboratories has stated that for a Metal Halide fixture
to maintain its ETL Listing, that an additional tempered safety lens is required in the event that the arc-tube and outer glass fail.
This will prevent the spread of Mercury.
17.Can I run a 1000 watt bulb in my 400 watt lighting system?
No! The internal components of the ballast are designed to send the correct voltage and current for the rated lamp. Mixing lamps
and ballasts will result in premature failure and will void the manufacturers’ warranty. Consider the size area you want your
garden to be prior to making a lighting purchase. It is better to grow into a fixture than out of one.
18.Can I run a 430 watt bulb in a 400 watt lighting system?
Yes, the internal components of 400 watt and 430 watt ballasts are almost identical. You will only get 400 watts of light out of the
430 watt lamp, however.
19.Do I need to wear gloves when handling an HID light bulb?
Manufacturers do not state that gloves are required when handling their lamps. It is recommended that your hands be thoroughly
washed prior to handling HID lamps though.
20.What is a conversion bulb?
A lamp that operates on the opposite ballast it was originally designed for. For example, a 940 watt conversion lamp is an HPS
lamp that runs on a 1000 watt Metal Halide Ballast. There are also MH lamps that are designed to operate on HPS ballasts. These
bulbs allow the grower to purchase the ballast of their choice and offer the flexibility of growing a variety of plant types by simply
changing the lamp they need.
General lighting questions:
1.What is HID Lighting?
HID lighting stands for High Intensity Discharge, which is a special type of lighting that is much more intense (brighter) than other
types of lighting available. An HID lighting system consists of a ballast, reflector, socket and lamp (light bulb). The ballast acts like
the engine, converting and driving energy to illuminate the lamp. HID lighting options include High Pressure Sodium (HPS), Metal
Halide (MH), Mercury Vapor and Low Pressure Sodium. The two typically used for plant growth are HPS and MH systems.
2.What is Color Rendering Index (CRI), Color Temperature (K) and Lumen?
Color Rendering Index is a subjective measurement of how well a lamp source renders colors. A measurement of the degree of
color- shift an object undergoes when illuminated by a light source when compared to a reference source of comparable color
temperature. Incandescent light is assumed to have a CRI of around 100 so it will render all colors correctly. MH only has a CRI of
about 70, so only 70% of colors will be rendered correctly. HPS has a CRI of 22.
Color Temperature is not how hot the lamp is. Color temperature is the relative whiteness of a piece of tungsten steel heated to
that temperature in degrees Kelvin. HPS has a warm (red) color temperature of around 2700K as compared to MH at 4200K,
which has a cool (blue) color temperature.
What is important to remember about these two terms is that CRI readings, of two sources, can only be compared if their color
temperature is equal. You cannot compare the CRI of HPS (CRI=22) vs. Metal Halide (CRI=70) because the color temperatures are
dif erent (2200K vs. 4500K).
Lumen is a measurement of light output. It refers to the amount of light emitted by one candle that falls on one square foot of
surface located at a distance of one foot from the candle. Traditionally, lumens have been the benchmark of a lamps ability to
grow plants; meaning the brighter the lamp the better the plant. However, studies have shown that a broader color spectrum
lamp will perform much better than a lamp with high lumen output, especially when it comes to plant growth.
3.What is the difference between MH and HPS with regards to plant growth?
MH lamps provide more of the blue/green spectrum, which is ideal for leafy crops, and/or plants that are in a vegetative (actively
growing) stage. MH lamps provide a more natural appearance in color and are typically the choice for plants that have little to no
natural light available. HPS lamps provide more yellow/orange/red spectrum, which is ideal for most plants that are actively
fruiting and flowering. In addition, HPS lighting is the choice for growers looking to supplement natural sunlight. Ideally, the
horticulturalist will use MH to grow their plants and HPS to fruit and flower their plants.
4.What is the difference between HID and Fluorescent lighting with regards to plant growth?
Traditionally, fluorescent lighting was used for seedlings, cuttings and plants with low light-level requirements and HID was used
for established plants and plants with higher light-level requirements. Advances in fluorescent lighting technology, however, have
provided more options for horticulturists. T5 fluorescent lighting is the latest in plant growth lighting. T5’s high-light output
combined with its low heat and energy consumption makes it an ideal light source to grow a broader array of plants.
5.What are the benefits of using T5 fluorescent lighting for plant growth?
T5 lamps provide the ideal spectrum for plant growth. Photosynthesis rates peak at 435 nm and 680 nm. A 6500K T5 lamp has a
spectral distribution with relative intensity peaks at 435 nm and 615 nm. This equates to very little wasted light energy in terms
of plant growth. T5 lamps promote incredible health and vigor of seedlings and cuttings. Root development is superior relative to
other lighting sources. While T5 lighting is excellent for starting seeds and cuttings, it’s also able to produce enough light for full
term growth. Because of their minimal heat output, T5 lamps can be placed 6” - 8” above the plant canopy which maximizes
photosynthetic response. Unlike conventional fluorescent lamps, plants grown under T5 lamps do not have to be rotated to the
center of the lamp. T5’s slim diameter enables better photo-optic control of the emitted light, increasing efficiency in the form of
even light distribution.
Environmental Impacts of T5 (at a glance):
◦T5 lamps have a diameter of 5/8” – smaller is better when it comes to manufacturing, transportation and disposal.
◦Reduction in raw materials and components needed for manufacturing.
◦Reduction in lamp and fixture packaging materials due to relative size.
◦T5 are constructed of 40% less glass than T8.
◦T5 contain 30% less phosphor than T8.
◦T5 contain 3mg of mercury. 70% less than T8.
◦Longer lamp life means reduced maintenance cost and less going to the landfill.
.6.What are the major differences between HID ballasts and electronic ballasts?
Frequency output to the lamp and energy conversion from electricity to usable light are the biggest differences between HID
ballasts and electronic ballasts. HID ballasts produce a frequency of 60 Hz. Electronic ballasts vary from manufacturer to
manufacturer, but the frequency produced can be 400x that of an HID ballast. HID ballasts produce more heat than electronic
ballasts, thus making electronic ballasts more energy efficient. You will not, however, save money on your electric bill by using
electronic ballasts. HID lighting has been available for 60+ years, while electronic ballast (especially 400 watt and higher) is a
relatively new technology.
7.Are electronic ballasts more energy efficient?
Electronic ballasts are more efficient at converting electricity into usable light. Since your power bill is based on kilowatt-hours and
not efficiency, a 1000 watt electronic ballast will cost you about the same as a 1000 watt HID ballast to operate.
8.How much energy will my light use?
An average lighting system will increase your electricity cost about $8 to $20 per month. The exact amount depends on the
wattage of the system and the number of hours operated. To calculate your cost, multiply the bulb wattage X the number of
hours of operation and divide by 1000. This figure is the number of kilowatt-hours of electricity used. (Example: a 400 watt lamp
running for 18 hours will use 7.2 kilowatt-hours). Check your power bill for the cost of each kilowatt-hour. Then multiply the
number of kilowatt-hours used by the cost of a kilowatt-hour (K/hr) to figure the cost to run your light for that many hours.
9.Do I need special wiring in my house for my lighting system?
Lighting systems are available in a variety of voltages. The standard used by most gardeners is 120 volts / 60 Hz which plugs into
a standard wall outlet. Other voltages may require special circuits and receptacles. Always contact a licensed electrician if the light
you purchased has special voltage requirements and never exceed more than 75% of the rated ability of the fuse/breaker. (For
example: use no more than 15 amps on a 20-amp circuit.)
10.What voltages are available for HID and Fluorescent lights?
HID systems are available in 120 volt, 208 volt, 240 volt, 277 volt and 480 volt - All at 60 Hz. Fluorescent lighting varies, but most
are available from 100 volt to 277 volt and 50 Hz or 60 Hz.
11.Will I save on my electric bill if I run my system with 240 volts?
No. Electric companies base your electrical bill on Wattage, not Voltage or Current. While ballasts wired for 240 volt will draw less
current and run a little cooler than one wired for 120 volt, it will not save you money on your electric bill.
12.How often do I need to change my light bulb?
Most lamp manufacturers rate their lamps by “Average Life Hours” and usually claim 10,000 to 24,000 hours. These ratings are
based on when the lamp will completely fail to come on. They do not factor in loss of intensity or loss of color. HID lamps lose
intensity and color through normal use. This is OK if you are lighting a warehouse, but when it comes to plant growth, these
losses can mean wasted electricity and poor plant performance. Serious horticulturalists recommend that you replace your lamps
after 6000 hours of use. This equates to using your light 16 hours a day for one year.
13.How long should I run my lights?
This depends on the type of plants and whether you have natural sunlight available to your garden. As a general rule, when you
are in a vegetative stage of plant growth and you have no natural sunlight, run your lights 14-18 hours a day. If you have natural
sunlight, it will vary because the sunlight may or may not be direct. It will take a little experimenting to find the best length of time
to run your lights. If you are actively fruiting and flowering, the rule is to run your lights 12 hours a day if you have no natural light.
14.How high do I need to hang my lights above my plants?
The higher the wattage the further away you want the light to be from your plants due to the amount of heat. HID lighting will be
further away than a fluorescent fixture because of this. When mounting your lighting fixture take into account the type of plant
and how tall the plant will grow. You want to keep the light as close as you can, but not so close to burn the plant. A simple rule
is “if it is comfortable for the back of your hand, it will be a safe distance for your plants”. Doing a little research on the type of
plant and where it comes from will help in determining how much (or little) light your plants like. With fast growing plants, you may
need to check the hanging height on a regular basis as plants that get too close to the lamp will be severely burned.
15.How big of an area will my light cover?
The size of the garden area will determine the wattage you need. If we assume that the plants will get no sunlight, a 1000 watt
light will cover about 7 x 7 feet of growing area. A 600 watt will cover 6 x 6 feet, a 400 watt will cover 4 x 4 feet, and a 250 watt
will cover 3 x 3 feet. These sized areas would be considered the “Primary Growing” areas. These lights will light-up larger areas,
but plants placed outside of the Primary Growing area, will stretch and bend toward the light; a phenomenon called phototropism.
Keep these areas of coverage in mind when using multiple fixtures. The best results occur when the areas of coverage overlap.
16.Why do I need glass to get the ETL Listing on a Metal Halide light?
The inner arc tube of a Metal Halide lamp contains mercury. Eddison Testing Laboratories has stated that for a Metal Halide fixture
to maintain its ETL Listing, that an additional tempered safety lens is required in the event that the arc-tube and outer glass fail.
This will prevent the spread of Mercury.
17.Can I run a 1000 watt bulb in my 400 watt lighting system?
No! The internal components of the ballast are designed to send the correct voltage and current for the rated lamp. Mixing lamps
and ballasts will result in premature failure and will void the manufacturers’ warranty. Consider the size area you want your
garden to be prior to making a lighting purchase. It is better to grow into a fixture than out of one.
18.Can I run a 430 watt bulb in a 400 watt lighting system?
Yes, the internal components of 400 watt and 430 watt ballasts are almost identical. You will only get 400 watts of light out of the
430 watt lamp, however.
19.Do I need to wear gloves when handling an HID light bulb?
Manufacturers do not state that gloves are required when handling their lamps. It is recommended that your hands be thoroughly
washed prior to handling HID lamps though.
20.What is a conversion bulb?
A lamp that operates on the opposite ballast it was originally designed for. For example, a 940 watt conversion lamp is an HPS
lamp that runs on a 1000 watt Metal Halide Ballast. There are also MH lamps that are designed to operate on HPS ballasts. These
bulbs allow the grower to purchase the ballast of their choice and offer the flexibility of growing a variety of plant types by simply
changing the lamp they need.
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pH/EC/TDS Meters
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