Robyn - all of my container soils go into a big heavy duty trash bag which is stored out on the patio over the winter. I'm not saving my soil from the potato grow bags as the plants developed some type of blight. Instead, I'll use it to top-dress some ornamental beds.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize that we can't eat money. Cree proverb