Tomatoes are really the star of the garden show, and like any celebrity, they can be a bit of a diva. If you’ve grown your own tomatoes before, you know you have to work to keep them happy or they won’t reward you with tasty fruit. You have to prune them, fertilize them, support them…

And perhaps most important of all, you have to water them. These divas need deep and consistent watering to produce good-quality fruit. Large fluctuations in watering can cause issues like splitting fruit (not ideal) and blossom end rot (best to avoid). Watering the wrong part of the tomato plant can even lead to fungal issues (really bad news). 

Don’t worry. We’ve dealt with these tomato divas for years, and we’ve rounded up the most important tips to keep them happy in your garden. Here’s how to water tomatoes to build strong root systems, prevent pests and disease, and support healthy fruit development.

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DIFFERENT METHODS TO WATER TOMATO PLANTS

There are several different ways to deliver water to your tomato plants. The best method for you will depend on the size of your vegetable garden, your climate, and the amount of time you want to personally spend watering.

The different ways to water tomatoes include:

  • watering by hand with a watering can
  • watering with a spray hose
  • adding oyas from Growoya throughout your raised beds
  • installing a drip irrigation system
  • hiring a professional to install a formal irrigation system connected to the vacuum breaker of your home
  • doing nothing and continuing to buy all your produce from the grocery store

For best results, I recommend using some kind of automated drip irrigation system. You can attach a timer at your spigot so that your plants get water at regular intervals, even while you’re away. There are lots of DIY kits, like the grid system from Garden in Minutes, that allow you to easily install your own drip irrigation.

Check out this post for more information on each of the different watering methods. Now let’s look at the 4 best practices to keep in mind when watering your tomatoes.

 

1. WATER SLOWLY AND DEEPLY

Long and slow watering is ideal for good root growth. By watering deeply, we mean really saturating the soil so that it’s moist at least an inch down. (It’s easy to check by sticking your finger into the soil. It should be wet all the way to your mid knuckle.) This is preferable to more frequent but shallow watering because it encourages the roots to dig down deep to find water instead of staying close to the top layer of soil. 

For optimal deep watering, I recommend a soaker hose or drip hose. These systems are left on for a long time and deliver water right at the root level, minimizing water lost to evaporation. This is a super efficient and effective watering method. 

If you’re watering with a spray hose, use the softest spray setting to mimic gentle rainfall. You don’t want to splash a bunch of water up onto the leaves of the plants because many of the diseases that affect tomato plants actually come from the soil. Go back and forth across the soil as you water, noting how long it takes for little puddles to disappear. Keep watering until the puddles take longer than 3 seconds to be absorbed. 

young tomato in a raised garden bed with drip irrigation lines for watering.

2. WATER TOMATO PLANTS AT SOIL LEVEL

For the health of your plants, you’ll want to aim your water at the soil surrounding the roots, rather than the leaves. Wet leaves can lead to fungal growth and disease. Water droplets can also burn the leaves of your plants on bright, sunshiny days.

Again, drip lines are ideal because they deliver water right to the root zone of the plants. If you’re watering with a hose, we recommend using a long watering wand. With a watering can, do your best to hold the spout as close to the soil as possible. Don’t be afraid to hold stems and leaves out of the way so you can more easily get right to the base of the plant.

3. WATER TOMATO PLANTS IN THE MORNING

The best time to water your tomato plants is in the early morning, before the heat of the day. Like early birds, plants wake up refreshed and ready to absorb more nutrients in the morning. If your watering system is automated, set it for around 5 a.m. If you’re watering by hand, try to head outside as early as possible.

The next best time to water for those of you who are not early risers would be in the early evening, once the sun loses its intensity. This isn’t as ideal as the morning because a lot of the pests that might consider visiting your tomato plants at night are attracted to wet conditions. Watering early in the day gives the soil surface time to dry out a bit before pests go looking for their nightly hang.

Should you happen to look outside and see your tomato plants struggling in the middle of the day, you can always give them a little supplemental water. Just make sure to aim water around the base of the plants so you don’t get water droplets on the leaves while the sun’s strong.

young tomato plant growing in soil in the ground in the morning time.

4. GROW TOMATOES IN GREAT SOIL

Your soil type makes a huge difference in moisture retention. The ideal soil for your tomatoes and other fruiting plants will hold a little bit of water without letting the roots of your plants sit in a bathtub for too long (which can cause them to rot). During the heat of summer, having soil that retains just a bit of moisture can actually keep the surface of your garden cool longer, which means your tomato plants might be happy to continue growing. 

I recommend growing tomatoes in raised beds filled with great soil that’s rich in organic matter, especially if you live somewhere with clay soil in the ground. My recommended well-drained soil mix is topsoil, compost, and coarse sand. You can find more info about this soil blend in this post

tomato plant growing in great soil

COMMON TOMATO WATERING FAQ’s

Unfortunately, giving advice like “water once a day” doesn’t really cut it. There are lots of different things that go into determining whether your tomato plants are getting enough water—everything from soil conditions and climate (including wind and sun exposure) to whether you’re growing in a container, a raised bed, or the ground. Here are some A’s to common Q’s to help you better know when to water in your particular garden.

How Often Do You Water Tomato Plants?

Tomato plants don’t have a set amount of water they need. It really depends on a number of different factors like your climate and the tomato plant’s stage of growth (more on that in a bit). During warm, dry months, you’ll likely need to water your tomatoes every day.

The big thing to remember is to avoid inconsistent watering. Dry spells followed by lots of water can cause all kinds of issues, including stressed-out plants that basically call out to pests.

Try to water on a set schedule. This is obviously a lot easier if you have drip irrigation set up on a timer, but even then, you might need to make adjustments based on the amount of rain you’re getting. Always check the moisture level in the soil before watering. You’ll only need to water if the soil is dry down to at least an inch when you do the finger test (see below).

How Do I Know When to Water My Tomato Plants?

Your tomato plants will give you cues about your watering habits. Yellowing leaves are usually the first indicator that your plants are getting excess water. Wilting or curling leaves, on the other hand, are both signs that your plants are getting less water than they need. Brown leaves usually signal pretty severe dehydration.

You can also look to the soil for clues. An easy way to check soil moisture is to do the finger test. Just stick your finger into the soil, and if the soil feels dry down to about your second knuckle, it’s time to water. If the soil surface is dry and cracked, your garden probably needed water several days ago.

How Much Water Do Tomato Plants Need?

Tomato plants typically need between 1 and 2 inches of water a week. The right amount of water, though, really depends on the stage of growth. Mature tomato plants don’t need as much water as tomato seedlings recently transplanted to your garden. Young seedlings haven’t developed good roots, so they need water to be right at the surface of the soil or they’ll dry out. Even if you have drip irrigation installed, you might need to water by hand every single day (even twice on a really hot day) for the first couple of weeks after you’ve transplanted seedlings.

Here’s the thing: new gardeners often confuse overwatering with giving too much water, when really it’s about the frequency of watering. For established tomato plants, it’s better to water deeply and then let the soil dry out a bit than give shallow but frequent waterings. 

How Often to Water Tomatoes in Pots?

Container-grown tomatoes will need to be watered more frequently than those in raised beds or in the ground. That’s because the soil will dry out much faster at the top. Pots are also prone to retaining way too much moisture down below. To prevent root rot, make sure your pot or container has drainage holes in the bottom.

Water until you see water running out the bottom. And as always, do the finger test before watering so you’re only giving your plants a drink when they need it. If the soil in the pot ever pulls away from the edges, you need to up your watering ASAP.

TROUBLESHOOTING ISSUES

Here are some common tomato issues related to watering and what to do about them.

Cracking Tomatoes

If your tomato fruits are cracking, you’re probably not being consistent in your watering. The fruits are growing so fast their skin can’t keep up. Your tomato plants are likely still healthy even if the fruits are cracking, and consistent watering can quickly solve this issue. If the fruits are cracked on the plant, I’d discard them since the cracks can attract fungus, bacteria, and fruit flies. If the fruits crack once you bring them inside and rinse them, you can eat them or cut around them for immediate enjoyment. Just don’t use cracked fruits for canning.

Blossom End Rot

This is when your fruits have ugly brown spots on the bottom, kind of like bruises. It happens because over- or under-watering has prevented the plant from taking up calcium as needed. Remove the affected fruits, and then adjust your watering as needed.

Fungal Diseases

Avoid fungal diseases by watering the base of the plants, not the leaves, and trying not to splash dirt up onto the leaves. The first sign of disease could be yellowing, wilting, or spotted leaves.

cherry tomatoes with blossom end rot

I hope you’re excited to implement these watering tips with whichever watering system you’ve decided is best for you and your little garden divas. One last piece of advice is just to visit your garden every day. That way, you can check on the soil moisture and observe how different factors like wind, temperature, and sunlight can impact your garden. You’ll get a better feel for your watering schedule as you go. 

Let us know in the comments if you have any questions about watering your tomatoes.