Cracked tomatoes. Blossom-end rot. Fruit that tastes watery instead of sweet. Many of the biggest tomato-growing frustrations actually start with one simple mistake: inconsistent watering.
Below we delve into how often tomatoes really need water – and the signs you’re giving them too much or too little.
But if you’re new to the world of growing tomatoes, you may not be sure of exactly how much water to give them. If they don’t get enough, the plants won’t fruit, or the tomatoes will be undersized. If they get too much, or if you water inconsistently, you risk grainy tomatoes, split skin, dry patches, blossom rot, or other issues.
How to tell your plants need watering
While you might think a wilting plant is a sign that it needs water – and it sometimes is – it’s not the most reliable indicator. Young tomato plants can wilt in the heat, even if they have enough water.
The best way to tell is to feel the soil. If the top inch of soil feels dry and crumbly, chances are that your tomatoes need to be watered.
How to water tomatoes
The goal when watering tomatoes is to keep the soil consistently moist. If the plant spends too many days dry then gets a deluge of water, the fruit will develop dry patches on its skin, which then split when it attempts to grow – and the split skins can lead to rotting.
However – and this is important – you don’t want to douse the leaves or stems of the plant if you can help it. Moist leaves and stems can lead to unwanted fungal rot.
Therefore, the best way to water tomatoes is close to the ground, directly into the dirt around the base of the plant. Water deeply, so the water penetrates to the roots, and water regularly. Water early in the morning so any water that gets on the leaves can dry quickly; this will help prevent the spread of disease.
A drip irrigation system is also a great way to keep the soil consistently moist. And be sure to add a layer of mulch around the base of the plants; this will help prevent disease from spreading and water from evaporating.
How often to water seedlings
Seeds and seedlings need the most frequent waterings, but they don’t need a lot of water at any one time. If you’re growing seedlings indoors or in small pots, simply make sure the soil is consistently moist to the touch. If you water them once or twice a day, don’t fully soak them, and don’t let the plants sit in water. Just make sure the soil doesn’t dry out.
How often to water young plants
As the plants grow, water them once a day or every other day. You’ll want to water them a little more deeply, especially as they get bigger, to help them develop deeper roots. If the soil dries faster, water them a little more often. If it remains moist for a couple days, then you can back off to avoid overwatering.
How often to water mature plants
Once the plants are mature and before they fruit, extension agents recommend 1 to 1½ inches of water a week. This can come from a rainstorm or the hose. The best way to tell if you need to get out and water is to set out a rain gauge. Keep a log of how much rain (if any) you’ve received and supplement what’s needed.
One exception is if you’re growing your plants in pots or other containers. Because more of the dirt is exposed to the environment, the soil is likely to dry out faster and may need to be watered much more frequently.
Other factors to consider when watering
Some other factors to consider are the soil environment: if the soil you’re using is sandy and prone to dry out, your tomatoes will need to be watered more often (and may need some fertiliser as well).
If the soil is dense and muddy or clay, which retains a lot of moisture, your plants may need to be watered a little less frequently.
You’ll also want to consider what kinds of tomatoes you’re growing. Some plants are bred for growing in pots, for instance, with shallow root systems that need less water. Others that are bred to produce tomatoes all summer (instead of a single crop) and to grow in the ground, will have larger root systems that require a lot more water to stay moist.
Summer gardening edit
John Lewis VegTrug
Metal Square Digging Spade
Christopher Michel is the former Senior Food and Gardens Editor at Country Living Magazine. Chris has well over a decade of experience writing and editing for national magazines and websites, mostly in the food space, such as Cooking Light, The Kitchn, Rodale’s Organic Life, and Bon Appetit. Prior to that, Chris worked in a variety of food spaces in New York City. In 2022, Chris completed the Alabama Master Gardener’s Program hosted by the Alabama Cooperative Extension System. Chris lives in Birmingham, AL, where he enjoys running, reading, and cooking for his wife and two girls.
Charlyne Mattox is the Food and Crafts director with over 20 years recipe development, recipe editing, and crafting experience. Prior to starting at Country Living in 2014, she worked in the crafts department at Martha Stewart Living and Martha Stewart Kids before attending cooking school at the Institute of Culinary Education in New York City. She was nominated for a James Beard media award while a senior editor at Real Simple magazine and authored a cookbook Cooking with Seeds.
When not in the kitchen she loves to garden, focusing on growing flowers and kitchen herbs (of course), watering her 25 house plants, and knitting scarfs or hats she will never be able to wear in the always hot and steamy Alabama.
