warm roots colder air?
I've heard many sub-tropicals and even tropicals can tolerate lower air temps than they normally would, if the soil is kept warmer.
When I grew citrus under lights in my basement, I was able to get better results with 55 degree air and 65-70 degree soil than I did when it was the other way around.
However, aside from pads and cables, which only seem to have enough power to warm a couple inches of soil, is there a reasonable way to warm a large pot of soil for a larger plant, like a citrus, guava, or banana, in this situation?
I suppose you could just wire up a soil cable for each pot, and maybe intertwine it w.roots but that would be a nightmare come repotting time!!
Any experience here?