Cloche is French for "bell"

About two weeks ago, I put cloches on two of our raised beds. The cloches protected the soil from excessive rain, which allowed the beds to dry out pretty quickly. I got very lucky since we had a spate of sunny days which rapidly increased the temperature inside the beds and thus warmed up the soil. Garden books recommend a "soil thermometer" and while I don't think a regular thermometer will work, my meat thermometer does a great job getting a quick reading.

Within a couple of days of planting, the peas were sprouted and by now, they're a couple inches tall. I think I got close to 100% germination so we're definitely going to need to do some thinning. I've been watering every couple days (more like every five days).

We also have carrots, leeks, mustard greens and parsley planted under the cloches, all of which have sprouted. It appears that some volunteer tomato plants are coming up. I think I'm going to let them grow big and transplant them to another bed rather than just plucking them all.

The cloches are made out of 1/2 inch Schedule 40 PVC pipe with 4 mil translucent builder's plastic stretched over the hoops. The pipes are slipped over 3/8" rebar (1/2" rebar is too thick to chance it) which is pounded into the ground. I used some 2-foot rebars, some 4-foot. Something like 3 feet would be perfect, but either works. My beds are about 4 feet wide.

I experimented with two different construction plans. On one frame, I made the hoops out of two pieces of 5ft long pipe joined with a tee (or a 4-way cross for the middle two hoops). In between each hoop, there is another piece of pipe that connects each hoop to the next hoop in the bed. That turns the whole frame into a single unit, and prevents the outer two hoops from being pushed in to the middle by the taut plastic. This is definitely the preferable method. You can see the pipes holding the plastic up at the apex of the hoops on the left bed.

The second frame just consists of four hoops being 10ft long pieces bent over. I had intended to chop these in half and build it like the other frame, but the tees and crosses aren't tight enough since there is an incredible amount of pressure at the apex of the bent pipe, right where the tee is, so they just slip out. I bought these pipes from a different store than the first set. After staying bent for another couple weeks, I should be able to chop the 10-foot pieces in half and put in the tees and crosses like the other bed. Of course I could have used some PVC cement/glue, but then I wouldn't be able to disassemble the frames for storage. You can see this frame on the right of the picture - just four hoops, no top pipes.

In both cases, the plastic stretches across the frames and is secured by some very large rocks. When you pull the ends tight and put a heavy enough rock on the end, the system holds up well to high winds and heavy rains. Now if I could just figure out a way to make it warm all the time...