Q: Can you tell me where I can get information on the effects of over-the-counter drugs on plants? I know some people put aspirin in potting soil near the root of their plants and in the water of flowers in vases. I’m told this helps them grow and stay fresh.

A: There has been a good bit of research on the use of “floral preservative” products on various cut flowers. Most contain glucose, anti bacterial agents and an acidifier. The actual results have been mixed, although some florists swear by the stuff.

Homeowners have tried solutions of lemon-lime soft drinks, mouthwash, vodka, bleach, and aspirin to extend the life of their cut flowers. These are usually the same folks who put banana peels, egg shells and coffee grounds on their plants.

Other than occasional fruit fly infestations, I don’t think these homeowner preparations and practices hurt plants. On the other hand, I can find no scientific research on the effects of drugs on plants.