I am getting ready to recover the tops of 2 coldframe lids and am wondering about the best material to use. The coldframes are made from 2 wooden box shaped frames that were going to be tossed until my scavenger husband spotted them. Last fall we covered the sides with plastic sheeting, leaving the top and bottom open. My husband then framed two lid-sized retangles which we also covered with the plastic (cheap Walmart type). We set the open bottoms onto our raised beds, surrounded the north, east and west sides with straw bales, and raised the most fantastic lettuce and spinach through the winter that I've ever eaten. The sides are still intact, but the plastic on the lids has fallen apart through the summer (weathering I'm sure), so they need to be recovered. I now have all kinds of tiny bits of falling apart plastic in my beds, which is kind of unnerving me, and I'm wondering if it will cause any problems, toxicity-wise to the soil in there? I'm also wondering what is the best thing to recover the lids with. I probably won't worry about the sides till next spring as they're still intact, but I do need to find out what the best materials would be that aren't too expensive. Any ideas would be appreciated. One box is about 6'x3', the other about 5'x4'. Both are just under 3' deep.