Clever set up! I solarize 20-30 gal batches by spreading it on plastic or metal sheeting, wetting and covering with clear plastic. I leave the plastic on until it starts to degrade which is usually a few weeks. I've never measured the temp but it gets too hot to touch. I've also solarized by putting plastic down on the mix in large pots (20gal+). I know the heat is not getting very deep but assuming the pathogens/weeds would be in the upper part of the mix. Rod in North Central Texas, USA Gastil said: I am experimenting with solarizing soil. > > >