Q. I was away on vacation for several weeks and my houseplants were seriously overwatered. How can I tell if they have suffered permanent damage?

A. Root rot is the most common problem associated with overwatered houseplants and flooded outdoor plants. The severity of the damage depends on the amount of time the roots were waterlogged and how much of the entire root mass was affected. To check for damage, remove each plant from its pot and check the condition of the roots. Healthy roots are firm and white; infected or rotten roots are soft, darkened and often produce an unpleasant odor. If most of the roots appear healthy, trim out any damaged ones and remove any yellow or dead foliage. Repot the plant using a fresh soilless mix and resume normal care. If more than 50 percent of the roots are damaged, you might consider discarding the plant.