Would using soil heating cables be an economic way of keeping plants frost
free in the winter? I am presuming that the heat will rise and keep the rest
of the plant warm. I would expect that not as much heat will be lost via the
top of the greenhouse because it will at least have a chance to heat up
something and some will get stored. Or is soil warming strictly for
propagation? Or does everyone just use heaters?
I know this sounds early to be asking but my cacti buying feet are itching
and so I need to sort out winter residences before buying too many to be
able to use windowl edges.

thanks
amber