When watering tomatoes in pots or your garden, getting it right is critical.
Too much or too little water can mean the difference between healthy plants with loads of juicy tomatoes or ones that are droopy and provide little fruit.
To learn how often you should water tomato plants and understand the best time and way to give them a drink, follow this guide.
When you water tomatoes the right way, you’ll be able to enjoy ripe, delicious tomatoes all summer long!
How Much Water Do Tomatoes Need?
Most tomatoes in the ground will require 1.5-2 inches of water weekly from either rain or irrigation.
The amount of water tomatoes require will depend on:
- Plant age
- Soil structure
- Whether it’s potted or in-ground
These circumstances can alter how much water tomato plants need.
For instance, young tomato seedlings should get some water daily to keep the soil moist. When the roots aren’t struggling to find water, the plant can devote more energy to healthy development.
Mature tomato plants need enough water to reach deep roots that grow on average two feet down into the garden soil.
You may need to increase water application if the soil structure is sandy or rocky and drains quickly.
Tomato plants in pots generally need more water than those in the ground as lighter, fluffier potting soil dries out quicker than garden soil.
Excess water drains out the bottom of your pots, leaving the tomatoes thirsty if you don’t monitor them daily.
When temperatures rise, more moisture evaporates from the soil. The tomato plants may need watering twice a day to prevent the top layer of dirt from getting hard and crusty making it difficult for future waterings to penetrate the roots.
If you reside in a region with consistent rainfall during the tomato growing season, you may not have to water your tomato plants manually.
The variety of tomato plants also plays a role in how much water they need. For example, bush-style varieties need more water to sustain the heavier amount of stems, leaves, and fruit.
When To Water Tomatoes
Water regularly using the details of your particular tomato garden’s growing conditions as a guide.
If it rains long enough on one of your watering days, you can bypass using the hose.
Use a rain gauge or soil moisture meter to ensure you’re watering your tomatoes properly at each session.
You need the water to penetrate the soil deep enough so it reaches the roots of the tomato plant.
A moisture meter is ideal for potted tomato plants to see if the soil is drying quickly.
A schedule of every four or five days may be fine at the start of the season, then increase it to every two or three days as summer days get hotter.
As days begin to cool down again, or your tomatoes are heavy with fruit, you can reduce watering to every five to seven days.
The best time of day to water tomato plants is early in the morning or later in the afternoon after the sun moves across the sky and isn’t as intense.
Since tomatoes grow best in direct sunlight, watering during the heat of the day will lead to much of the liquid evaporating instead of hydrating the plant.
Water droplets on leaves can also cause sunscald as the liquid burns off from the heat or sunburn to the flesh of the fruit.
When To Stop Watering Tomatoes
Experts state that you should stop watering your tomato plants in the middle to late summer. The plant will survive on the occasional rain shower and water found deep in the soil by the long taproot.
The reasoning is that an under-watered tomato plant senses the “end of life” is near. This genetic response triggers the plant to expend energy into forming more fruits and less foliage.
Fruits that do grow will ripen quicker when there is less water.
Varieties such as Brandywine and Sungold thrive under such conditions, which is hard for a gardener to understand until you see the results.
Do note that lack of water will cause tomato stems to droop during this time, especially when they are full of growing tomatoes. Use supports to keep the plants upright and fruit off the ground and away from pests.
The exception to this stop-watering rule is tomatoes growing in pots, raised beds, or any other container.
The lack of trapped moisture inside pots will cause plant death if you stop watering the tomatoes inside. The roots are incapable of digging deep to locate bits of moisture like those planted in your garden plot, so never stop watering tomatoes in pots.
Can You Overwater Tomatoes?
Yes, you can overwater tomatoes. An overwatered tomato plant will cut off the air pockets in the soil, drowning the roots.
Symptoms of an overwatered tomato plant are:
- Yellow leaves
- Root rot
- Leaf roll
- Fruits that are tasteless
- Fruits that split open
All of these symptoms are easy to spot, but by the time you do, it’s often too late to save the harvest from the damage and produce a good quantity of tasty, unsplit fruit.
Many gardeners mistake leaf roll, wilting stems, or falling leaves as a sign the tomato is lacking water and proceed to water even more.
The only real way to determine if tomato plants are overwatered is to pull one up and check the root system.
Dark roots indicate overwatering, as well as them having a slimy texture.
You can often save tomato plants that are not too far gone by draping the plants with plastic during rain to allow the soil to dry out and let the roots recover.
Best Way To Water Tomatoes
Water Deep and Slow
Never water tomatoes so quickly that most of the liquid flows away from the plant before it soaks into the ground. Watering too fast pulls nutrients from the topsoil and washes them away, so your tomatoes lose out.
You want to allow the soil to absorb the water slowly so your tomato plants get a deep drink.
The easiest way to accomplish good tomato plant watering is to use a drip irrigation hose that releases water about an inch or so from each plant’s stem in your garden.
A slow drip will absorb fully into the ground yet keep tiny air pockets open that roots need to breathe.
You can also let your hose run at a trickle and move it along the soil as each area becomes sufficiently wet.
Water The Soil Not The Plant
Try to avoid dousing the entire tomato plant with water if you’re using a hose or sprinkler.
Damp foliage attracts pests and disease, and that water never reaches the roots and instead evaporates away.
Always apply water to the soil around the plant for the best results and the least amount of waste.
As water soaks into the soil surrounding the tomatoes, it encourages the smaller roots to spread outward.
This building of roots higher up in the soil creates a more stable plant that can hold up better as the tomatoes grow and ripen.
Don’t Panic Water
It’s a mistake to automatically water tomatoes in containers or in the garden that you see wilting or having the leaves curling up at the hottest time of the day.
This mid-day droop is the way all plants protect themselves against extreme heat or sunlight exposure.
By curling up, stems and leaves reduce the sun’s exposure to the plant’s surface, slowing water loss through evaporation.
If you see your tomato plants drooping during the hottest part of the day, leave them be and recheck them in the evening.
In most instances, the plant will fully recover, which indicates it’s getting plenty of water. If you feel the plant’s mid-day heat-exposure reaction is too harsh, you can opt to add a shade cloth over the tomatoes to diffuse the light.
Use Mulch and a Water-Indicating Test Plant
Mulch goes a long way toward regulating the soil moisture around your tomato plants and adds nutrients as it decomposes.
Potted tomato plants will gain even more benefits from mulch as a deep layer can increase the time between watering by a day or two.
Planting impatiens next to your tomatoes is a quick way to detect under-watered tomato plants. Impatiens quickly wilt when they need water, which tells your their neighboring tomato plants will need water too.
Tomatoes are a favorite garden plant because they need little care and produce such a versatile fruit.
Using the information above on how often you should water tomato plants, you can increase your tomato bounty by watering the right amount, at the right time, in the right way.
We all want a successful gardening season, so give these methods a try when your tomato plants are performing as they should!