I was totally out of space in the house for seedlings, and many need to be “bumped up” into larger pots, taking more space. And I need to seed more. I make a “hoophouse inside the hoophouse” in the spring for tomatoes and such, with two electric heaters in it. I wanted something more energy efficient. So, I figured starting on the ground rather than table top (those wire tables we use for CSA distribution) would be a good place to start.
It will hold 72 flats, and was half full by the end of the first day.
Step one took several days: Hoe the soil to loosen an unfrozen layer, rake aside to expose next layer, wait a few hours or a day, repeat. I had purposely over the years sloped the soil inside angling toward the south to be at a better angle to intercept fall/winter/spring sun. We frequently “undo” things. Usually the soil doesn’t freeze except on the very edge, but I had the green wagon of potting mix and stacks of pots here, which shaded the area. Leveling it was a two person job.
Step 2: Trim a few inches off the long edge of four sheets of foam board, to best fit four rows of plant flats and to make a “lip” around the bed. Wrap the edges in duct tape. Rip 2 x 4s to make spacers and risers.
Step 3: Hot glue spacers, outer lip, and cable clips to foam boards. Put them down, and duck tape them together. Glue lip around outside. String roof gutter heating cable. You can see this in the bottom right of the top photo.
Step 4: Get a half inch, over foot long drill bit and drill holes in the ground to put the conduit cover supports in. A lot faster to write than do – the soil was frozen HARD. Should have used a fatter bit. Put all weight on the conduit and PUSH. Drill again. Push again, several times for each hole, and finally it will break through to unfrozen ground. Well, some. I am hoping warmth will work its way down the conduit and thaw more so I can push the south row in deeper – so there is less space to heat.
Step 5: Plug the cable into a thermostat that comes on at 35 and off at 45. Wait for the sun to set and the air to cool to less than 35 to test. The cable barely got warm. Slight panic. Too late to do anything tonight.
Step 6: Get on the email and Facebook farm groups and ask for advice. Advice was to put an inline thermostat on it and crank it up to 75. Somewhere I have an inline thermostat that will do that, but I don’t want the air temp to be that warm. I just want to keep things from freezing. In the meantime, sleep on it.
Step 7: Plug the cable in without a thermostat and see if it gets warmer today. Relief, it does. Maybe it was just too cool the previous night for the outside of the cable to feel warm. Tuesday was sunny and wonderful in the hoophouse but barely above zero outside.
Step 8: Water seedlings in dining room with warm water to at least start them out warm. Bring plants out from the house, two by two in a bread tray covered with a flannel sheet. Cover empty area with empty flats and fill with water. Two reasons – keep the plastic flats from melting and water is a good heat sink.
Step 9: Pull row co
ver out of storage bag. The second one is large enough and not full of holes. No one has nested in and eaten it. Unroll it, and it is wide enough! That went better than expected. Clip it on and stretch it out. Fold back for double layer. And again for triple layer. I could fold again for a fourth layer, but enough is enough. Even three layers block too much sunlight so need to be rolled back during the day. Unroll painters plastic and stretch over and cut. It isn’t quite wide enough to fit to the ground on one side, but it does on the coldest side closest to the side of the hoophouse. It keeps warm air from rising through the row cover at night.
Step 10: Shovel off the basement Bilco door and bring out four old sheets of foam board that I’ve used to shield the sweet potatoes and squash from cold windows. Carry them out to the hoophouse. At night, lay them out on top for extra insulation.
Take deep breath. Tell yourself that everything you’ve taken out there is replaceable – either onion seedlings can be bought in or I have lots of seed and time to reseed others.
This morning – 39 in there! It only got down to zero outside last night. That isn’t a lot of leeway with below zero nights still forecast, but watching it today, the soil in the trays is collecting heat and the water in the empty flats is collecting heat, so it is almost warmer than I want, and I think it will hold through a below zero night.
