QUESTION: What are the signs of overwatering tomato plants?
ANSWER: Overwatered tomato plants can look a lot like underwatered plants, so if you are having a hard time telling the difference, pay attention to whether you see these signs when the soil around plants is still moist.
Overwatered plants may have wilted or yellowed stems and leaves, or the leaves might develop bumps and blisters or fall off entirely if plants continue to get too much water.
Another way to tell overwatered plants from underwatered ones, once the case is severe enough, is to check the roots. A plant that has received too much water for a long time may have roots that turn dark in color, in contrast to the pale color of healthy roots, or the roots may have a slimy texture.
You can rescue an overwatered plant in some cases by gently pulling it up, shaking off excess dirt, and resting the roots on a stack of two or three newspapers. Leave the plant on the newspapers until much of the excess water has soaked up.
Then plant it again in a container that just fits its roots, filling in around the plant with compost. If too much rain is the culprit, you can always hang a plastic sheet or tarp over an overwatered plant, removing the sheet when rainfall ceases.