I love the Hoop House at our Market Garden. I love that I can harvest spinach in March. I love that I can plant my tomatoes in late April and still be picking into October. I love that it was 85 degrees in there today and 70’s in January are a reality in my little microcosm. But as I mature, it is the more ephemeral things that matter… how it provides an ‘anchoring’ structure in our little .2 acre plot; something more substantial to draw the eye and provide contrast to row after row after of vegetables; the smell and feel of warm soil in January. The picture above shows how the rye/feild pea cover crop is coming in. Got a late start (as usual – “real” jobs get in the way ya know?), but it is doing alright. The tilled strip in the middle was the last 200#’s of potatoes to come out of this plot, and has a .5″ high stubble of winter wheat coming in.
In years past I have planted spinach and mache in the hoop house, but always put it in so late that I never get a harvest until March and this year is no exception. I typically get good growth and about 3 weeks prior to harvest (it takes forever with the short days in the winter) we get nailed with the Deep Freezes in early January when it gets down to -10 or so. This kills everything flat. The roots regrow in Febuary for a good harvest, but I would like to see what I can do to take the edge off that one or two weeks.
I also have another winter problem. I have arrangements with some local restaurants to compost their organic waste. This nets us 100#’s or so a week… every week. From November through April that means I have several cubic yards of slobsicles in my compost bins. Building up my capacity to handle 4 months of gorp was the primary driver of our new Bin Of Dreams. That bin is located on the north side of our garage and without direct sun, it takes a LONG time for 1500#’s of gorp to thaw out. Will Allen at Growing Power composts year round in his hoop houses… perhaps I could as well. So this year I am trying to kill both these birds with one stone. The windrow is designed to be 4′ wide and has a 24″ tall fence to contain it somewhat and give me a 3-4′ height without a 8′ base width. Eventually this will be 20′ long. I have dreams of following the thermophyllic composting bacteria down the windrow (no turning) with composting worms. Can I extend both my composting and greens season with the simple movement of 1500#s of gorp into the hoop house? Time will tell.
In the past 2 winters I have had buckets and trash cans full of water in an attempt to add some thermal mass to the hoop house. As I have said, it gets to be 80+ in there with 50-60 degree temp differences to outside air on good days. But with only a single layer of plastic it sheds btu’s like a sieve. The thermal mass in previous years has not been enough, it simply freezes solid eventually and effectually adds a cooling effect to the hoop house. Rat Farts. This year I have added a large fiberglass crate that hold several hundred gallons of water. As you can see in the picture, to help this out, I have surrounded it with a foot thick layer of leaves for insulation on 3 sides, and will plant the spinach directly to the south. In a further attempt to extend the season I amy dig out some row cover I found laying around and cover the spinach/compost/crate to keep the warm air around the plants. Finally the entire Hoop House will get a 4′ wide “foundation” mulch to keep the frost from creeping in as long as possible while the north wall will get as many leaves piled against it as I can find. Will this be enough to combat the utter lack of R value in the Hoop House? Time will tell. What is likely is that a double walled Hoop House with a bubble insulation system will be the way to go, combined with these techniques, if I want to go 4 season.
On a side note, I am trying to function stack the thermal mass. I have added about 5 gallons of leaves and some finished compost to it to make the well water a bit more nutrient rich. Then I walked down to the river and scooped up 5 gallons of river water and made sure to get a bunch of sludge from the bottom. This water is full of critters and microorganisms. I dumped this into the crate to “inoculate” the water and in a week or two I will add a handful of feeder goldfish. Now it is very likely in my first stab at aquaculture I am dooming these goldfish to a cold death as fish cubes, but if they somehow don’t freeze solid the 250 gallons of microbe rich ecosystem should keep them alive. And if the temps allow them to stay alive I will have also proven that I can sustain temps high enough to overwinter lake perch. Fish Fry anyone?