Hotbed complete

I've constructed a hotbed in our front yard to grow some early tomatoes and radishes. It looks thus:

Yeah, okay, you say. But hold your cotton-picking horses. I say, there's something a little bit odd about this photo. I agree: on first glance, the hotbed does look a little bit wonky. It looks like one of our usual three dimensions was a little out of it this morning, but fear not - the window that I based the shape of the frame on is trapezoidal. Only the right end is rectangular. I believe it used to be an old sliding glass door. Farmer Christoph probably knows more about it, since he's the one who gave it to me.

I attempted to follow the shape of the window in constructing the frame, and pulled it off with a few imperfections here and there. I'm pretty sure the tomatoes won't be able to tell the difference.

I constructed the frame out of dismantled, reformed, and reassembled wooden pallets. One finds an endless supply of discarded pallets in downtown Nelson's back-alleys.

I filled the frame walls with plastic foam insulation that the local florist has flowers delivered in and would otherwise discard, if it weren't for people like me dropping by to rescue it. I folded sheets of it into shapes that nestled perfectly into the frame walls. Inside the frame I covered the insulation with sheets of discarded hardboard and chipboard that I found in dumpsters and on the side of the road.

And the hotbed frame was complete. (It sounds easier than it was.) I then layered the bottom few inches with sticks and twigs I pruned from the bushes in the front yard to improve drainage of the bed.

Finally I filled the frame with four large wheelbarrow loads of just barely composted compostables: Oso Negro coffee grounds, sawdust, kitchen scraps, and straw mixed with chicken manure. Most of it was only a couple weeks old. I watered the bed thoroughly between loads. Christoph says that compost will be the most active if it has the moisture of a wrung-out sponge. I probably filled the box with between 1' and 2' of compost. But I hear it will start sinking soon as it begins to decompose.

I've been monitoring the temperature of the air immediately above the surface of the bed. It seems to be staying above 9ºC, and usually it hovers between 13ºC and 21ºC on overcast days. On sunny days, it quickly exceeds 40ºC, so I'll definitely have to be on top of venting the box on warmer days. When I'm satisfied that the temperature is remaining steadily warm, I'll shovel a 6" layer of soil on top of the compost and plant my tomato seedlings and radish seeds. I expect to be able to do that within a few days.

But man, next time I build a cold frame or hotbed, I'm not so sure about this pallet customization business! It's not very rewarding work. Those pallets are terribly hard to take apart. I think plywood is your best bet. It's just hard to come across large sheets of it for free. I do still want to build a cold frame; maybe I'll come up with something clever...