01 Dec 2007,Father Haskell in news:8238b2c6-6172-
:

Most plants grow a LOT better when soil temperature
is above 60 F.

though i suspect most plants won't like root temperatures ridiculously higher than air
temps.

2 gallon heated planters -- does anyone
make them? I'm tempted to roll up a seedling mat and
place it into the pot before pouring in soil, but I'm not sure
that wouldn't be a fire hazard -- maker Hydrofarm says
not to place insulating materials on top of the mat.

i wound't expect that insulation value to be much higher (if not lower) than a flat of
perlite of on top of the mat on a wood 2x bench in a greenhouse.

i think having a part of the mat overlap another part would be a worse spot-overheat
pitfall.