Recycled Solar: Double-Glazed Hot Cap Cloche

I was cleaning out my storeroom the other day and came across another recycled solar device that I was fooling with a few years ago.  A one liter clear plastic bottle makes a good hot cap or cloche when you cut the bottom off it.  Plant a seedling, pop the bottomless clear cap over it, and you protect  the seedling from the cold.  It probably adds between 5 and 10 degrees F over the outside temperature by protecting the seedling from the wind and by capturing sunlight in a small, closed space.  My twist on this idea was to find different sizes of clear plastic bottles which could nest one inside the other making a double-glazed hot cap cloche.  A double-glazed hot cap cloche might be able to protect the seedlings even better, keeping that small, closed space even warmer than the outside air.

This afternoon, I planted two tomato seedlings in my garden using this device.  We'll see whether it works.