Reflectix
Roy Herold (Mon, 08 Nov 2010 14:33:46 PST)

I beg to differ regarding the use of impermeable plastic for covering
plants in the winter in Massachusetts. It *does* work.

Most of the big commercial nurseries around here that grow potted plants
cover their outdoor stock with Microfoam. This is a closed cell
polypropylene foam that is around 1/8" thick. Typically it is put over
pots or beds after a hard freeze, and removed in March. An additional
covering of white plastic film may be used. Note that everything is
white to reflect sun, and minimize freeze-thaw cycles.

I know home gardeners who have successfully used it, too.

I agree that it would be foolish to use plastic in warmer weather, but
that's not what we're talking about.

Reflectix might work so long as it does not become brittle in cold
weather. Microfoam might be more practical and cheaper, however, if you
can use a 270 foot long roll. And styrofoam would also work if used
properly, as Adam observes.

Most nurseries stopped using hay a long, long time ago.

--Roy
NW of Boston