We view our crop protection structures at Simple Gifts Farm as representing a pyramid of increasing levels of protection.  The more elaborate and permanent structures at the top of the pyramid get us through the coldest months of winter.  Two weeks ago, I talked about our low tunnels, which are the bottom of the pyramid for the winter months.  Today, I’m going to talk about the next step up the pyramid—caterpillar tunnels. 
            We bought and built our two caterpillars last fall with the help of a loan from Common Capital, a local business-support non-profit. These caterpillars are very low-tech greenhouses.  The main structure consists of a series of posts that are used for the top rail of a chain link fence.   There are benders available which can bend these fenceposts into a curve.  Two curved fenceposts are linked together to form a half-round.  Then we drove smaller posts into the ground every five feet(the hardest part of this construction project, which we expect to get a lot easier once the jackhammer we ordered arrives in the mail).  The half-rounds fit into the ground posts, and then secure a sheet of plastic on top with a zig-zag pattern of ropes. Within a day, we had two 300-foot long greenhouses constructed.  They are called caterpillars because they can follow the contours of the land rather than having to have a nice level spot for construction.  Here’s a picture of the tunnel soon after it was constructed last fall:
We built this tunnel over some crops that were planted last fall with our usual field planting equipment: kale, spinach, and salad lettuce.  We also planted in, later in the fall, some onion sets that we will harvest as scallions and some leftover seed garlic that we will be harvesting as green garlic.  In future years, we will use these structures to protect late fall plantings of things like head lettuce and baby bok choy for harvest in November and December, and then start new crops in the middle of the winter for spring harvest.  Here’s Jeremy in the tunnel last fall.  That’s the same kale that we are harvesting today on the right.
One of the beauties of these structures is their flexibility.  It takes some effort, but we can take them down and put them up somewhere else.  Yesterday we took down our caterpillars, leaving the spinach and scallions to fend for themselves (at this point, they can take the frosty nights we are experiencing with just a little bit of row cover to protect them.).  We will be re-building them to protect an early planting of cucumbers that will be getting planted today or tomorrow.  The early cucumbers we have planted in the past have been a welcome reintroduction to “solid food” in the early summer—this year we will have about 4 times the ground area in early cucumbers than we have had in previous years, due to our caterpillars!  Here’s a picture of the caterpillars’ deconstruction process from yesterday:
That nearest crop is the scallions, which should be coming to the share next week!