Skip to content

Watering tomatoes – when and how often is right? This is how much water the plants need to grow well

Growing tomatoes is one of the greatest passions of amateur gardeners. Harvesting the tasty vegetables from their own garden and enjoy them fresh is always a real pleasure. But before it comes to the harvest, you must first cope with the care. If you have already planted the tomato plants in the garden or greenhouse, then now comes the question about watering. In this article, you will learn how to water tomatoes so that they thrive and reward you with a bountiful harvest.

What happens if you water tomatoes too much or too little?

How to avoid mistakes when watering tomatoes

To grow successful tomato plants , proper watering is essential. Unfortunately, this is also one of the practices that many gardeners do wrong.

At best, you water too little and deprive the plant of water, which leads to weak growth. If you overwater it, the roots rot, which in turn leads to weak growth. In the worst case, you go too far in either direction and ultimately kill the plant. It’s a delicate balance.

Warnings aside, it’s not hard to water your tomato plants properly. It may take some practice at first, but once you know when, how often and how much to water, you won’t have to deal with the panic of watering properly.

Why proper watering is important

Ripe tomatoes to harvest in the garden

Watering is, of course, an essential part of caring for tomato plants. Without water, the plants simply can’t survive. But watering in the right amount, at the right time and in the right way is more than a standard care task.

Proper watering of tomatoes can prevent a number of problems. Among them:

  • stunted growth
  • root rot
  • poor quality of fruit
  • low yield
  • susceptibility to pests and diseases
  • blossom end rot
  • cracking
  • Yellow and falling leaves

Most importantly, though, proper watering is good for the fruit. Tomatoes are mostly water, and the plant needs a lot of it to bear fruit in the first place. To get a good harvest – the goal of every gardener who grows tomatoes – you need to start with proper watering.

How to water tomatoes properly

Watering tomatoes in the greenhouse tips

Providing your plants with water is important, but how you water is just as important.

Water deeply and slowly

The most important thing about watering is consistency. Your tomato plants need a steady supply of water to support their continued growth. This consistent supply is not guaranteed if you water the soil quickly every few days and leave the plant to its own devices.

If you water too quickly in large amounts, the water will run off rather than penetrate the soil and reach the roots where it is actually needed. If you water slowly, you soak all parts of the soil – not just the top layer. This allows the plants to absorb more water over time than if you were to flood the soil, even if you use the same amount of water.

Drip irrigation system

If you don’t feel like (or have the time) to stand around for hours slowly watering your plants, we have good news – you don’t have to. Installing a drip irrigation system will solve the problem for you and take a lot of the work off your hands. It’s easy to buy such a system and install it around your tomato plants, or you can simply build it yourself with items you have around the house.

As a general guideline, the soil should be watered to a depth of at least 15 cm. Again, a drip irrigation system can help by providing a steady supply of water that penetrates deep into the soil and doesn’t just stay on the top layer.

Water from the bottom

When watering tomatoes, be sure not to wet the leaves. The roots bring the water to the parts of the plant that need it. Focus on the roots by watering the soil at the base of the plant and leaving the leaves out of the equation.

Don’t water too much directly around the trunk, as this can cause the soil to wash away or the trunk to rot. Focus on the area around the plant and water slowly and deeply for best results.

Watering tips for tomato plants how to do it correctly

Check the soil moisture

Sometimes damp, sometimes dry, tomatoes don’t like it. Therefore, the soil must be regularly moist – only the surface should dry. The easiest way to check this is with the thumb test. However, make absolutely sure that the soil does not dry out completely, otherwise the fruits may burst – regardless of whether they are already ripe or not.

The right time is crucial

Water tomatoes better in the morning or evening

When watering tomatoes, there are several little things to keep in mind to get everything right. In addition to the “how”, the “when” is also very important.

Water tomatoes in the morning or in the evening?

The right time to water plays a crucial role in tomato growing. Ideally, you should water the vegetable plants in the morning, so that the leaves can dry by noon. Watering in the afternoon or evening will leave the plants wet, which can lead to fungal diseases. At noon, the hottest time of day, you should also not reach for the watering can, because the water will evaporate quickly before the roots have a chance to absorb it.

How often should you water the tomatoes?

How often to water tomato plants in the garden or greenhouse which water

This is probably the most common question when it comes to watering. Unfortunately, there is no simple answer to this. Tomato plants don’t live on an easy-to-follow schedule, and simplistic advice like “water every 3 days” is not meaningful. How often you need to water depends on a number of factors:

Age/size of the plant.

In the early stages of growth, young seedlings need a lot of water to develop deep roots. As the plant grows and the roots advance further into the soil, they may require less watering if the soil is deeply saturated.

Larger plants with extensive root systems also need water more frequently than smaller plants because water is absorbed and used more quickly.

When planting

When transplanting your young tomato plants from the pot to the outdoors, be sure to water them well.

Too dry soil can cause the tomato to burst


In hot weather, water in the soil evaporates faster, so there is less water available for the plants. During the hot summer months, you need to check the soil once or even twice a day to make sure your tomato plants have enough water.

Fruit stage

Tomato fruits need a lot of water during the development phase. However, once the fruits are fully formed, too much water can cause the skin of the fruit to crack. If you limit watering after the fruit has formed, the tomatoes may also taste better.


After heavy rains, plants do not need to be watered for a while because they can absorb water deep in the soil. Prolonged rain can also cause the soil to become too wet, resulting in root rot. To ensure that your plants always get enough water – no more, no less – you need to work around the rain.

How to water tomatoes correctly

And what about tomatoes in greenhouses and containers?

If your tomatoes are planted in containers, they will need to be watered more frequently because the soil dries out faster in planters. In the greenhouse, the plants do not get rainwater, so the water requirement is higher.

These are just some of the factors that affect how often you need to water. Instead of following a schedule that doesn’t take into account what your plant needs at the right time, check the soil every day or two and assess the moisture content. Don’t water until the top layer of soil – about an inch or two deep – has dried out. In this way, you avoid the risk of over- or under-watering that comes with fixed schedules, since plants receive water only when they really need it.

How much water does a tomato plant need?

How much water do tomato plants need

How much water you should give your tomato plants is hard to say. According to experts, tomato plants need about 4 inches of water per square foot of soil each week. However, converting this into the right amount of water at the right time is a difficult task. The amount may also depend on the factors mentioned above.

In other words, it’s better to assess the soil before watering and adjust as you go, rather than sticking to a set amount. As long as you water slowly and deeply and don’t oversaturate the soil, the amount of water you use will depend on the nature of the soil and the plant rather than fixed numbers.

Watering may require some trial and error at first, but you’ll develop an intuition in the process that will help you better understand your tomato plant’s needs in the future.

How to water tomato plants correctly slow deep

What kind of water is best?

Tomato plants love lime-free water, with rainwater being the perfect choice. However, you can also water tomatoes with tap water. For this, it should stand for a few days, for example, in rain barrels, and be sure to have an appropriate temperature (ie, not cold water).

More tips and tricks for watering tomatoes

Watering tomatoes with a time-honored trick.

Practical tricks certainly like everyone, especially if they can save the plants and, consequently, the harvest in the kitchen garden. Since watering tomatoes should be done slowly, you can try the trick with the PET bottle, which is also convenient when watering cucumbers.

How to water tomatoes on vacation trick

How to water the tomatoes when on vacation?

If you plan to go on vacation during the growing season of your tomato plants, you should think about an alternative watering method, so that the plants do not die or suffer damage in your absence. Here the trick with the clay pot will help. For this you will need two clay pots (unglazed), a small tile and hot glue or silicone. You first cover the drain hole of one pot with the tile and then glue the second pot upside down on top. You dig the whole thing into a prepared hole next to each tomato plant so that only a few inches of it are visible. You then pour the water into the water reservoir through the open hole of the top pot. This method will provide your plants with water for about 5 whole days. To prolong the effect, you can place a layer of mulch around the tomatoes. This will further protect the soil from drying out.

Otherwise, you can always ask a friend or neighbors to water the tomatoes in the morning when you are on vacation. Professional gardening help can also be hired to do the job in your absence.