Modern commercial fruit and vegetable production is fraught with logistical and other problems. For instance, vegetables and fruit are often harvested long before they achieve their peak nutritional value, since they must endure many days of transit and, depending upon the type of produce, perhaps months of storage before appearing in supermarkets and finally on your dinner plate. Yet more troubling is the fact that U.S. fruit and vegetable production is highly centralized in one state that is now suffering one of the most severe droughts ever experienced. Our country has depended upon California to produce a high percentage of many crops that people regularly consume. While the numbers vary slightly, roughly three-quarters or more of the nation’s lettuce, carrots, tomatoes, grapes, broccoli, and numerous other foods come from this single state.1 To frame it another way, approximately one-third of all produce consumed in the United States comes from just a single valley—the Central Valley—in California.2 This near-total reliance upon one market basket is neither reasonable nor responsible and places the entire nation’s produce supply at risk.
THE LOGICAL ALTERNATIVE
Fresh fruits and vegetables grown locally offer numerous advantages over the centralized model. Since local produce only travels short distances, fruits and vegetables can be picked at their proper times of ripeness, generally ensuring a higher nutrient content and better taste. Once harvested, the flavor and nutritional content of most fruits and vegetables steadily decline, further underscoring the importance of obtaining food as locally and regionally as possible and cutting down transit, warehousing and display times.
With all these considerations in mind, the impetus to expand and extend local produce yields has never been more pressing. But many parts of the nation have relatively short growing seasons that don’t support certain popular crops, unless you discover that those seasons can be extended through various low-tech tools.
If you doubt the power of technology to skew the seasons, just take a look at the photo. Yes, those are Kentucky bananas. My neighbor has been growing bananas in his very large greenhouse for years, along with limes and lemons, too, that fill the corners of his temperature-stabilized growing space.
Certainly not everyone has the resources to build such an expansive facility. Yet after looking at the cost versus production value and food savings, you realize that for any large family or community with space, such a setup is a long-term cost saver. The good news is that less expensive and lower tech solutions are available to any and every grower.
GAINING SIX WEEKS ON THE SEASON
Kentucky’s growing season is generally marked by the annual Kentucky Derby, celebrated the first Saturday of May. Planting before that date for many crops is considered a gamble at best. Yet waiting to plant after May first may mean that many crops won’t be ready for harvest until July.
Low tunnels are a great solution to the question of how early to sow. Low tunnels are made by making hoops from either metal, such as EMT (electrical metallic tubing) conduit, or PVC pipe, or even wood, and then covering the rows of hoops with a material known as floating row cover/frost cloth or greenhouse plastic.
The floating row cover comes in a number of fabric weights—the heavier the fabric, the greater the temperature differential it creates underneath the cloth and the more protection it provides. The cloth is also water-, air-, and sun-permeable, allowing all three to pass through to the plants below, albeit, especially for sunlight, reducing the total amount with the heavier grades. The main brand names are Agri-bond and Dewitt.
Greenhouse plastic, on the other hand, allows full light permeability, but does not allow water and air exchange. Thus, its use requires a bit more care and prudence. Unseasonably warm stretches can turn a greenhouse into a bakery for cold-hardy and cool-weather plants. Depending on how you build your growing spaces, especially raised beds, supplemental water may be needed to ensure plant success.
DIY IS RIGHT FOR THIS GUY
Even for the relatively unhandy, low tunnels are a pretty simple do-it-yourself project. Lost Creek and Johnny’s Seeds both sell a basic hoop bending tool that allows you to take off-the-shelf EMT conduit and turn it into durable, aesthetically acceptable and easy-to-use hoops. A small group of gardeners, friends, homesteaders, or farmers could all chip in to buy such a tool and share it as needed.
Note that if you go the EMT route, you have your choice regarding what general width the final hoop will take— approximately three, four, or six feet. I personally like the six-foot bender and six-foot wide growing spaces. Whatever size you choose, make sure to plan various other components of your garden system to work with this size and that your row cover and greenhouse plastic are also rightly sized.
Once the hoops are bent, they need to be placed over your growing spaces. There are numerous methods to do so. I use 30-inch or 36-inch pieces of rebar driven into the ground. Rebar is sold in 20-foot sticks, so I prefer 30-inch pieces to reduce waste, but sometimes end row hoops need the additional support provided by a longer ground peg. I still get zero waste by planning ahead and cutting some extra 36-inch pieces to ensure that I use the entire length. The half-inch EMT conduit fits perfectly on the rebar sticking out of the ground. If I want to loft the tunnel for a slightly taller planting, I use connectors and extenders cut from the full-length EMT pipe down to the size I desire.
I do want to note that rebar or any other metal or wooden posts sticking out of the ground present a real danger if left exposed and uncovered. A simple trip and fall onto one can be quite painful or worse, so I am careful to pull rebar or other hoop pins when I pull the hoops. If you won’t be reinstalling the hoops, grab a bucket or bin and pull the stakes at the same time. This is for my safety and that of my family and friends.
To secure the fabric of plastic in place, again, there are numerous options. Some people use sand bags placed every few feet along the rows. Some use existing mulches and soil from their garden. Some use rope secures at the ends of rows with a heavy weight or sandbag. Do whatever works for you. Whatever method you use, be sure that the fabric or plastic cannot be blown about by the wind or that the materials used to hold it in place won’t damage the plastic or fabric. Small tears and punctures can quickly become larger holes and gashes and defeat the purpose of your covers.
BENEFITS OF SEASON BENDING
The ability to move formerly restricted planting times to new parts of the calendar offers many bonuses. There is the obvious benefit of having access to fresh, local vegetables long before or long after they would normally be available. But there are many other benefits as well. By planting out of normal season, pest and disease pressures for some plants can be substantially mitigated.
For instance, this year in late May we harvested almost our entire spring potato crop before the potato beetles had even begun to make an appearance. Our cabbage and broccoli similarly avoided most of the predation of cabbage worms and were harvested and eaten, fermented, or frozen not long after Derby day. Growing deep into the fall and early winter, and starting plants early in the late winter and early spring not only produces tastier vegetables for some crops like carrots and other cool-weather crops, but dramatically reduces pest problems.
Even more interesting, as my Amish banana-growing neighbor has shown, crops that a particular climate would have never normally permitted outdoors suddenly become possible. Also, since few people may be growing these crops, pest and disease and other problems may be substantially lessened.
EMT CONDUIT VERSUS PVC HOOPS
For numerous reasons, I prefer metal hoops over PVC hoops for my low tunnels. First, there is the environmental
toll of PVC production and the numerous toxic chemicals produced and released by its creation, recycling, and disposal. Second, PVC’s lifespan is miniscule compared to EMT conduit. Since the hoops are exposed to significant amounts of sun and temperature variations, both of which severely degrade plastics—especially extreme cold, which causes the PVC to become brittle and prone to cracking and breakage —PVC hoops will need to be replaced in as little as three years or sooner. On the other hand, EMT conduit can last a decade or more and, when no longer serviceable, can be recycled in most locales with relative ease and also might net you a small return fiscally in scrap value. While the EMT is slightly more expensive up front, the cost difference is negligible over time and environmentally preferable.
MORE INFORMATION AND RESOURCES
- I would be remiss not to mention and recommend Eliot Coleman’s The Four Season Grower.
- Hoop Benders: Lost Creek, www.lostcreek.net
- Agribond and DeWitt: While you can order these items off the Internet, shipping can be very high, so getting them locally from an independent organic garden or farm supply store is often best.
- EMT conduit and rebar are available at any building supply store or electrical supply store.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Fall 2014