Greenhouses And High Tunnels (Short Course)
There’s a really easy way to tell if aquaponics can be profitable year-round in your climate. Look around and see if there are any flourishing agricultural businesses that grow in hothouses or greenhouses; especially if they are hydroponics businesses.
Even if these guys shut down during the wintertime, or just during the worst couple months of the wintertime, this is an indication that you’re on the right track. If you find these, then you can be sure aquaponics will be profitable, because you have a number of advantages over either hydroponics or vegetables grown in the ground inside greenhouses. These are the reasons you will do better than these existing businesses:
1. Your produce is certifiable organic and can command much higher prices than conventionally or hydroponically-grown, chemically-fertilized and sprayed produce.
2. You have the income from the fish as well as the vegetables, and as the only nutrient input into these systems is the fish food; there are no fertilizer costs in addition as with every other type of growing technology.
3. The vegetables grow in about half the time, in about one-quarter the space they take up in the dirt, thus utilizing greenhouse space more cost-effectively than plants grown in a soil-type medium.
4. Organic aquaponics systems are incredibly stable and disease-resistant compared to hydroponics, and do not require nearly the maintenance that hydroponics does. They NEVER require draining or sterilization (we have large commercial systems that have been in constant use for eight years that have never been drained nor sterilized; they are self-contained, balanced aquatic ecosystems inside man-made containers).
If there are NO greenhouse businesses in your climate and area, that’s probably a good indication that there are some other adverse factors to be concerned with, to identify, and to deal with before making a large investment in greenhouse aquaponics.
Greenhouses: How to understand them and select the right one for you.
For readers who are not farming in Hawaii, or a similar climate, you may need protection for your crops in the winter, and perhaps even most of the year. This means a greenhouse, and perhaps even heating, if you have a cheap source of heat. How do you tell if you need a greenhouse? Ask the other farmers in your area. If they’re growing a produce item in greenhouses, you can too, with the added benefits of your produce being organic, and of raising fish in addition to the vegetables.
Greenhouses come in a confusing variety of types, shapes, materials, and costs. The cheaper ones let less light through and more heat out. The more expensive ones let more light in and less heat out. When you’re selecting a greenhouse, you need to strike a balance between the climate conditions you want inside, the climate conditions that will be experienced on the outside of that greenhouse, and what your budget can stand. Your local trusted greenhouse supplier, or a local farmer with a lot of experience growing with greenhouses, is the person you want to talk to about this. Don’t just let a salesperson sell you something or buy the cheapest thing you find on the internet.
The cheapest store-bought greenhouse is what’s known as a cold frame. These are usually semicircular steel frames with plastic sheeting stretched over the frame. They are easy to erect yourself, and relatively easy and cheap to repair if there is wind or hail damage to the structure. A good example of this kind of greenhouse is Conley’s CF Series 1000 Cold Frames (Conley Mfg. and Sales, 800-377-8441, www.conleys.com on the Web).
IMPORTANT!! There’s a terminally important thing you should know about greenhouses: they are modular and can be disassembled and moved. This may not seem important until you look around and see how many used greenhouses are on Craigslist and other web sales places, and how CHEAP they are, compared to new prices. Many greenhouse businesses that used to grow ornamentals (stuff you can’t eat!) have gone out of business in our current economy. There are others located on property that has been foreclosed, and you may be able to buy the greenhouse from the bank. You can often purchase these for pennies on the dollar.
Even if your prospective greenhouse has no plastic covering, or a rotten one, replacing this is usually quite inexpensive compared to the cost of the metal parts of the greenhouse. If you find one(s) that meet your needs that are reasonably close to you, you can take a crew there with a Ryder or U-Haul truck, a bunch of screw guns and air-powered ratchet wrenches running off a gas-engine powered compressor, and take the thing apart. The same crew can put it together again when you get home, if you have your building permit in place and a foundation for the greenhouse ready.
Make yourself a sketch of the greenhouse before beginning disassembly, and number each piece with permanent marker or lumber crayon. Bundle it up neatly, with similar pieces bundled together, all the bolts and screws separated in buckets or containers by size, etc. What you will arrive home with is the same package you would get from the greenhouse manufacturer if you bought a brand-new one, just for a fraction of the price! Look for other things you may need at the same place you buy the greenhouse; they may have spare fans, water walls, roof vents, etc. to sell. Purchasing a greenhouse for pennies on the dollar could make the difference between a profitable venture and a struggle.
IMPORTANT!! There are also sources of information for do-it-yourself greenhouses such as the excellent “Secrets to a Successful Greenhouse and Business” by T. M. Taylor, which gives all kinds of information for building greenhouses yourself; this book also has a ton of good general information about plants, marketing, integrated pest management (how to use good bugs to eat the bad bugs!), and much more.
More expensive greenhouses meet Building Code requirements, often have double- or triple-layer insulated plastic sheeting, either rigid or inflated, for insulation, and often have large venting systems for getting rid of summer heat as well as heating systems for keeping temperatures comfortable for the plants in the winter. A good example is the Conley’s 4000, 5000, and 7500 Series greenhouses. However, you need to be careful when purchasing a big greenhouse such as this, because the purchase cost is often the smallest of the costs you will be facing. Often the heating costs for propane in the winter, and electricity costs for fans, air conditioning, and water walls in the summer can dwarf the original cost of the greenhouse. It is these costs that will determine whether or not you can make money growing in a greenhouse, if your climate requires one.
Modified Environment Agriculture (MEA)
Modified Environment Agriculture (MEA) refers to any structure that protects a crop from the elements. While this could technically apply to floating row covers or shade structures, it more usually refers to those structures that are covered at least in plastic and are semi-permanent to permanent. Growing aquaponically, we’ve found several MEA techniques that benefited our production, even in semi-tropical Hawaii.
The most common MEA structures are hoop houses and high tunnels. Both are usually used for season extension and not year-round growth. There is a dramatic range of sophistication in the equipment used in these structures. For the most basic case, the plastic sides are rolled up for ventilation and there is no electricity to the structure – no fans, heat, supplemental light, etc. At the other end of the spectrum, there are high tunnels where there are fans and equipment for ventilation, electricity, supplemental light, and supplemental heat.
Links to pages with good information about high tunnels:
A USDA sponsored project involving Kansas State Research and Extension, University of Missouri Extension and University of Nebraska Cooperative Extension: http://www.hightunnels.org
This page from Rutgers University provides links to research results in the form of final reports for the projects conducted in 6 high tunnels spread over 2 locations. http://aesop.rutgers.edu/~horteng/hightunnels.ht