QUESTION: This year the spring has been really wet, with a lot of rain. I have also been watering them on the days that it doesn’t rain. I know that tomatoes need a lot of water, so that’s good, right? Can you overwater tomatoes?
ANSWER: Like any other plant, it’s definitely possible for your tomato plants to get more water than is good for them. Excess water can replace the air in the soil around the tomato plant’s root system, causing the roots to drown and eventually die.
Overwatering looks a lot like underwatering—that’s one of the things that makes overwatering so easy to do. Plants that have received too much water may have wilted foliage or stems, be discolored to yellow or brown, or their foliage can eventually just fall off. You may also notice fruit with cracks in it and bottom leaves that have bumps or blisters. As things progress, the blisters or bumps can start to have a cork-like texture.
Too much water in the soil can cause the root system to develop rot, discoloring the roots to darker than their initial healthy pale color and making them have a slimy texture. Finally, when your plants have been getting too much water, you’ll notice there may be standing water on the ground for hours after you water the plants.
Before adjusting your watering habits to a normal level, you’ll want to first give your plant a small amount of water each day. Remove any wet potting soil or compost from the container, gently brushing it from the roots, then place the roots of the plant on two or three stacked newspapers, which will draw out the moisture. Move the tomato plant to a pot just large enough to hold its roots, filling in around the edges with fresh compost. If rains are expected, you can protect a plant recovering from overwatering by draping a plastic sheet or tarp over it, taking it off again when the rain stops.