Watering tomatoes is all about watering slowly and watering deeply. Going slow and easy is the best way to ensure effective watering techniques for tomatoes. If you don’t have the time or patience to do it yourself, consider a drip hose or some other drip-irrigation method that will deliver water slowly and deeply into the soil for your tomato plants.
How often you water your tomato plants depends on how hot it is and how often they receive water naturally from the rain. In the heat of the summer, your tomato plants need water once every two to three days—and that includes natural rainwater. Once the fruit has set and started growing, you can scale back watering to only once a week. Tip: Dawn is the best time of day to water your tomato plants. Avoid watering during the hottest time of the day.
When watering tomato plants, direct the water straight to the soil and the roots. Don’t spray the plants from above. Spraying the plants from above can cause disease and pests to thrive on your plants. Also, watering tomato plants from above leads to premature water evaporation, unnecessarily wasting water. Using mulch can help keep water where the plants need it and also slow down evaporation.
Generally, 2 inches of water a week for plants in the ground is a good rule—and more often for plants grown in containers or pots. Many factors determine the right amount of water and the frequency of watering—including plant size, temperature, and amount of sunlight, for example. Try using a water gauge if you need to more closely monitor your water level. Or, by planting impatiens nearby, you’ll have a natural indicator of when to water your tomato plants. If your impatiens are drooping and dry, your tomatoes likely need water, too!
Rainwater is great for all of your garden plants. If you can collect rainwater, your tomatoes will benefit from that!
Tomatoes don’t like cold water, so fresh-from-the-well water might be a bit too chilly. If you have to use well water, let it sit for an hour or so until it warms up before using it to water your tomato plants.
If you’re using tap water, allow the water to settle for one to two hours before dispensing to help the tap water’s added chlorine evaporate before soaking the soil around your tomato plants.