If you are repotting a household plant, can you reuse last year's soil from your outdoor window boxes and garden pots? The answer is no, unless you are absolutely certain that the soil is free of any disease. Since it can be impossible to tell, the best way to reuse potting soil is to sprinkle it in the yard, where the sun has a chance to "bake" it, killing any disease as the soil eventually blends right into the ground.
ANDREWS MCMEEL SYNDICATION