can I 're-use' potting soil?
Last summer I purchased a cottage that came with many potted plants on the deck. In preparing for winter, I ripped out most of the plants as the previous owner had instructed and stored the pot & soil in a small shed. For others, I left the plants in place (mostly trailing ivy that I'd hoped would survive) and covered it with a tarp for the winter (the ivy didn't make it). The result is that I have many pots filled only with "old" soil. Is this soil usable, or must I buy new bags of potting soil? Thanks in advance!