Keep an eye on soil moisture and your vegetable garden. Even with drought restrictions, don’t let tomatoes wilt or dry out completely; that can encourage blossom-end rot. How much water do tomatoes need? Give tomatoes a deep watering two to three times a week and a little more if they look droopy. If your tomato plants are on a drip-irrigation system, figure a gallon per mature (and bearing) plant per day. Water before 8 a.m. to reduce chances of fungal infection and to conserve moisture.