How Often to Water Your Tomatoes—and the Best Way to Do It

The right schedule and technique for watering your tomato plants can mean the difference between sweet and juicy fruits and a garden full of cracked vines and withered blossoms.

While the precise timing between waterings varies by garden and a number of other factors, a few best practices for how and when to water remain consistent. Read on for expert-recommended advice on everything you need to know about watering your tomato plants for healthy tomatoes all season long.

Signs Your Tomato Plant Needs Water

The simplest, most effective way to determine whether your plant needs water is to touch the top of the soil, says Jessica Mercer of Plant Addicts. "If the top layer feels dry, it is time to water. If the soil is still moist, no watering is needed that day."

Droopy tomato plants can be a sign of dry soil or drought—but they're not a reliable indicator of whether your plant needs water. "Tomatoes will wilt or droop during drought or high heat," says Mercer. "Check the soil for moisture first before watering a droopy plant; if the soil is still moist, the plant is likely wilting because it cannot take up water fast enough to counteract evaporation."

How Often to Water Tomato Plants

As your tomato plant grows, its water requirements change—so the schedule that worked for you when the seeds were first planted will need to be adjusted as the season progresses.

Seeds: Every Few Days

Moisten a seed-starting mix before planting your tomato seeds, says Mercer. "Keep the media evenly moist by misting the plants every few days or bottom watering when the soil feels dry on top," she says. "Do not let the seed tray sit in water for longer than 15 to 30 minutes." Remove any water that collects in the tray under the plants; don't let the plants soak.

Young Plants: Up to Every Day

During the first week after planting your starts, you should water regularly as the plants adjust to their new homes; this could even mean every day if your soil checks turn up dry dirt. "You can slowly decrease the frequency after the first week to encourage the roots to grow deeper," says Mercer. "Make sure you continue to water slowly and deeply to help the roots develop drought tolerance."

Mature Plants: 2 to 3 Times a Week

"Once the plants have been growing for a few weeks, you can decrease the watering frequency," says Mercer. "Consistency is key here because you don't want to allow the soil to completely dry out or become overly soggy." Expect to give the plants between 1 and 1-1/2 gallons of water each week, in total, distributed over two to three watering sessions. 

Fruit-Bearing Plants: As Needed

Plants that are providing tomatoes need less frequent watering; too much can cause the tomatoes to crack or split. "On the other hand, underwatering may decrease fruit production, so continue to water the plants when the soil feels dry," says Mercer.

Other Factors to Consider When Watering Tomatoes

The right frequency for watering your tomato plants also depends on multiple factors, including the soil type, whether the tomatoes are in the ground or a container, the maturity of the plant, the size of the root system, and the weather.

Soil Type

The ideal soil type for tomatoes is fertile, loamy, and well-draining, says Mercer. "In sandy soils, watering will need to be more frequent to account for the fast drainage," she says. "Soils with a higher clay content retain water longer and require less frequent watering." Add organic mulch to keep your soil moist and extend the time between watering sessions.

Soil Volume

Garden beds, raised gardens, and containers all surround your plant with different volumes of soil. The rule of thumb: The smaller the soil volume, the more often you'll need to water. "Containers have a limited volume and require the most frequent watering because the soil dries out more quickly than garden beds," says Mercer. "Raised beds tend to hold moisture longer than containers but dry out faster than in-ground beds."

Tomato Variety

One of the key factors in how often a tomato plant needs water is the size of the root system, says Mercer. "A larger root system requires more water than a smaller one. Smaller determinate types, bred for containers, have lower watering needs than larger indeterminate types, like beefsteak or Big Boy tomato plants," she says.

Weather

Keep track of the sun exposure, temperature, and rainfall—all of which can affect your plant's watering schedule. "When the weather is hot and dry, plants will need to be watered more frequently, usually a few times a week for raised beds and daily for containers," says Mercer. "If plants receive at least an inch of rainfall a week, no supplementary watering may be needed. "

The Best Method for Watering Your Tomato Plants

Tomato plants should be watered at their base, slowly and deeply. "Slow, deep watering supports root development better than a light sprinkling of the soil surface," says Mercer. "Overhead watering can invite fungal infections such as anthracnose, so if possible, use soaker hoses or drip irrigation to water your tomatoes." Avoid sprinklers, which will moisten the stems and leaves more than the base of the plant; more water will evaporate than soak into your plants' roots.

Mercer also recommends tending to your plants during the cooler, earlier part of the day. "Watering in the morning before the afternoon heat kicks in can help reduce wilting and protect the plant from heat damage," she says.