Watering Tomato Plants – The Complete Guide

The best way to water tomato plants is to sprinkle near the base of the plant early in the morning, and then let the water soak in 6 inches of soil. Ultimately, the growth stage, soil, and organic content decide how much and how often you should water your plants. 

Don’t worry! I prepared this useful guide for watering tomato plants of different varieties, climates, and soil types. It will help you choose a healthy amount of watering at every stage.

I highly recommend daily watering during the growing season and gradually decreasing the watering as your plants mature. Now get ready to learn how to water tomatoes properly for better root development, rapid growth, and fruiting!

How Much Water Do Tomato Plants Need? 

Garden-grown tomato plants need 1 to 2 inches (2.5 to 5 cm) of water per week. Potted plants, on the other hand, need frequent watering. The water requirement of tomato plants varies with the following factors:

• The maturity of tomato plants 
• Whether the plants are growing in the ground or in pots 
• How much rain have you had 
• Different varieties of tomatoes  
• Soil type, quality, and organic matter 
• Climate zone and temperatures 
• Special production techniques 

That’s right; there are seven factors so that your tomato plants grow lush and healthy. 

1. Watering Requirements by Tomato Plants’ Growth Stage

You will soon find out that a tomato plant has varying watering needs as it grows. How much water tomato plants need depends on their four growth stages. 

Growth Stage of Tomato	Watering Needs
Seedlings	The medium should have the same moisture level as a wet sponge
Young Plants	Deep watering, twice a day in the morning and night
Mature Plants	1″- 2″ (2.5 – 5 cm) layer of water every week
Fruiting Plants	A weekly 1.5-inch-deep soak (3.8 cm)

Tomato Seedlings Water Requirement

Ideally, a tomato seed starting mix should have the wetness of a well-wrung sponge— not too dry and not too wet.  While watering tomato seedlings, make sure that the soil is wet well below the surface—water tomato seedlings twice a day, in the morning and at night. 

Young 12″- 3′ Tomato Plants Water Requirement

After transplanting, water your tomato plants slowly and deeply. Start by soaking the clay soil around the root area. Avoid leaving air pockets at this stage to help the soil retain moisture. If you put your finger two inches in the soil and it feels parched, your plant is not receiving sufficient water like other plants.

Mature 3’+ Tomatoes Plants Water Need

A plant that has grown 3 feet high doesn’t need frequent watering. However, you should remember to water them deeply with soaker hoses if the weather is particularly hot. You can install a rain gauge beside your garden tomato plant to keep track of how much water they are getting. 

Fruiting Tomato Plants Water Need

Spoiling your tomato plant with excess water will cause the fruits to split. Water once daily as necessary and avoid flooding. A general rule for growing tomatoes is to water them until it starts to seep out from the bottom.

2. Watering Requirement Depending on The Tomato Plants’ Growth Place

Tomato Plants Growing in Pots 

Container tomato plants naturally need more water than garden tomatoes. Since the roots can’t find water deep inside the soil, you will do the plant a big favor by watering slowly and deeply near the base of the plant.

Make sure there are drainage holes for excess water to clear away. With sub-irrigated planters, it’s easy to know when your plants need hydration. You can check the water level with SIPs and add water as needed. 

Tomato Plants Growing in the Ground 

It’s best if your garden tomato plant receives 1.5 inches (3.8 cm) of water in a week. But how does that work for a tomato patch? Let us break it down for you. You should pour 1.5 inches of water for every square foot of the garden soil.

In addition, you can add natural fertilizer to your organic vegetable garden. The best organic amendments for backyard tomato production are alfalfa meal, biochar, bone meal, compost, cottonseed meal, and neem seed cakes.

3. Water Requirements for Different Varieties of Tomatoes 

Nowadays, there are some droughts and heat-resistant tomato varieties. They have different watering guidelines compared to globe or cherry tomatoes. Therefore, avoid resorting to a uniform watering schedule for all types of plants in your garden. 

Pearson, Heat Master, Solar Fire, Summer Set, Amish Paste, and Yellow Pear are popular among the heat-tolerant tomato varieties. Correct watering makes these varieties less likely to develop tomato sunscald and other diseases. 

4. Water Demand based on Soil Type and Quality 

Clay soil retains water much longer than loamy or sandy soil. Tomato plants grown in clay soil will thus need less watering, even during dry spells and hot weather.

Struggling with clay soil is quite common since the material is thick. You may use coconut coir to improve aeration and moisture retention. Coconut coir makes heavy soil moist and lighter. 

Raised beds tend to dry fast, so regular watering is necessary. Never compromise with a drainage system for in-ground tomato plants. Too much water can lead to root rot.

5. Availability of Rainwater

For in-ground tomato plants, rainwater is a major source of natural water supply. Rainfall is taken into account in the 1.5-inch (3.8 cm) weekly water requirement. 

You can harvest rainwater in tanks and use it to grow tomatoes. If managed carefully, harvested water from heavy rain can be a reliable source to water tomato plants in the dry season.

Tomatoes have fragile skin that can easily crack under torrential rain. Consider a drip irrigation system for watering tomatoes. But make sure to turn it off temporarily if you experience heavy rainfall in your area. 

6. Watering Needs by Climate Zones 

Watering tomato plants in wet climate zones should be kept at a minimum. Root rot and blossom end rot are a few problems that arise when you put too much water in tomato plants. 

In hotter climates, the soil naturally dries faster and cracks under the sun. Therefore, you have to maintain a regular water supply in tropical areas with little rain. 

Always remember that a long, deep soak is better than a squirt of water every day. Water slowly, and avoid overcompensating your plants’ water requirements.  

Watering Dry-Farmed Tomatoes 

Dry-farmed tomatoes are grown in such a way that promotes deeper roots and intense flavors. There can be three waterings in the growing season. Irrigation is withheld once the roots have emerged. 

Without irrigation, the plants grow their roots far and wide to collect nutrients and water from the soil. This specialized production technique is adopted in wet regions with sufficient rainfall of 20 inches (around 50 cm). 

Before watering dry-farmed tomatoes, use a high water-retentive soil such as clay and plant the saplings 4 to 6 ft. apart. Under this system, water your tomato plants deeply while they are young. 

How to Water Tomato Plants: 5 Methods for a Healthy Harvest 

If you are new to growing tomatoes or have noticed blossom end rot on your beloved plants, you may change your watering method. Here are your options!  

1. Watering Can 

Most gardeners use a watering can for tending to their tomatoes. Our advice is— to get one with a rose spout to ensure correct watering.

This type of watering can spread water slowly in smaller streams. Water regularly near the plant’s roots and avoid harsh water pressure. 

2. Garden Hose 

You can use a soaker hose or a regular garden hose to water your tomato plants. Make sure you are not overwatering the seedlings or soaking the foliage.

The recommendation is attaching a nozzle to the hose to allow water to come out slowly. A soaker hose provides an easy way to hydrate all your tomato plants at once. 

3. Drip Irrigation 

One of the most effective ways to water plants is using a drip system. Under a drip irrigation system, water is passed through small tubes located at the base of your tomato plants. Drip irrigation ensures that each plant receives the correct watering and the same amount of water. 

4. Sprinkler 

You’ll be surprised to know that using a sprinkler is the least recommended option for watering tomato plants.

Sprinklers release water from above which drenches the leaves. Tomato leaves are prone to pest damage and diseases, so wetting them is not the best option.

5. Mulching 

Mulching helps soil retain moisture, increases nutrition, and prevents the onset of weed. A tomato plant that is mulched and well-watered can put forward the best yield.

Wood chips, grass, shredded leaves, compost, straw, and newspaper can be used for preparing the mulch. Always leave a two-inch gap around the stem so that water can comfortably reach the root zone.

The Best Time to Water Tomato Plants 

Watering tomato plants isn’t exactly rocket science, but you still need to be careful while watering tomatoes. Paying attention to the time and frequency will save you so much work towards the later stages of tomato production.

Time of the Day 

Tomato plants require plenty of sunlight in the growing season. So, the best time to water garden tomatoes is early in the morning. It allows them to absorb more water since less moisture is evaporated at dawn.

Watering at dawn also facilitates photosynthesis and other physiological activities. Never water tomato plants at night because there is no sun to heat the soil. With slow evaporation, standing water can create fungal problem that stunts root growth.

How Frequently To Water Tomato Plants?

The proper watering frequency varies with temperature and soil moisture, as well as the seed, vegetative, flowering, and fruiting stages.

As tomato seedlings sprout, they need proper watering two times a day. Be careful, though. Too much water can quickly flood the beds and ultimately kill the plants. 

PRO Tips for Watering Tomato Plants

Watering tomatoes without proper knowledge can affect your plant’s yield and overall health. Most beginner gardeners wish they had known about these four things when they started.

These tips will help with watering tomatoes the right way. 

Water Slowly 

For tomato plants, watering slowly can reap a good deal of benefits. An even layer of water is guaranteed to reach all the roots.

So, water around the base of the plant, avoiding the foliage and the stem, and take your time with it! Hastening this process can result in runaway water, which washes nutrients away from the soil. 

Add Topsoil and Organic Matter

If you want to water tomato plants sufficiently, adding organic matter to the top layer is a good option. Lawn fertilizer and grass clippings can protect your plants and enrich the soil. 

This combination is well-suited for dry climates as it increases the water retention power of the soil. Wheat straws and rice straws make good mulch for tomatoes. It breaks down beautifully and improves soil texture. 

Work Out a Watering Schedule 

You should be watering tomato plants based on the weather and growth stage of the herb. In low temperatures and high humidity conditions, the soil stays moist for a long time. Watering deeply now can, therefore, lead to mushy roots. 

Watch Out for the Warning Signs 

Your plants will give you signals if you add too much or too little water on a regular basis. Before it’s too late, check out the tell-tale signs of overwatering and underwatering tomato plants from here.

Underwatering Tomato Plants

Tomato plants receiving too little water can be identified by curling, yellow leaves, poor growth, and dry soil. The yellowing begins with older leaves at the lower part of the plant; if you notice these five signs in your tomato garden, water deeply once every day or twice when it’s summer. 

• The tomatoes are not hardening 
• Wilted older leaves 
• Curled roots 
• Stunted growth 
• Dried-up and cracked soil 

The correct watering method for chronically underwatered plants is to increase the frequency and consistency. 

With too little water, the plants suffer greatly from dry soil and poor nutrition. It is recommended to repot the plant in fresh soil with organic amendments so that there is less water loss moving forward.

Overwatering Tomato Plants

Pouring too much water on tomato patches will make the soil anaerobic and eventually cause root rot. Overwatering leads to the spread of harmful pathogens that stunt the growth of your tomatoes. 

But what happens when you overwater the tomatoes that are ripening? It can cause tomatoes to split open and have a bland taste and mushy texture. Signs of overwatering tomatoes include:

• Wilting and yellowing leaves  
• Fruits may develop cracks and have a mushy texture
• The blossoming end of the fruit starts to break down and rot 
• Roots appear reddish brown in color
• Slow growth and mushy stems

Fixing Root Rot in Tomato Plants After Too Much Water

When the roots turn dark brown and the leaves are wilting, remove the affected areas immediately and dispose of the soil.

To save tomato plants from root rot at this point, you need to repot them in fresh garden soil and deeply water the top layer. Water your container plants till water begins to seep out, and follow the 1.5-inch watering rule to allow optimal soil moisture.

Fixing Blossom End Rot in Tomato Plants   

Blossom end rot looks like gray water-soaked spots on the bottom of a tomato. The affected area sinks and turns dark and leathery. Unfortunately, once occurred, it can’t be cured, and the affected tomatoes are discarded. 

The good news is it’s easy to prevent blossom end rot so that it doesn’t spread to the entire garden.

• Keeping your tomato plants well-watered is the best way to prevent blossom end rot. First, you should remove the rotting tomatoes and use them as organic material for your compost.
  
• You can use crushed eggshells to increase the calcium content of the soil. It’s a common misconception that watering tomato plants with milk increases calcium. But realistically, it doesn’t help with moisture retention or increasing calcium levels.
  
• Spread a thick layer of organic mulch around the base of the plant. Use chopped leaves, grass clippings, straw, or shredded bark to prepare a two-inch deep mulch. Lastly, make sure you don’t over-fertilize. 

Tomato Watering – FAQ

1. How often should you water tomato plants in summer? 

You should water tomato plants twice every day in the summer season. Depending on growth, soil quality, and temperature, you may need to change the watering frequency later on. 

2. How to water tomato plants while you are away? 

An automated drip irrigation system will not only water slowly and deeply at the roots but also hydrate tomato plants according to a preset routine. It can help you water the tomatoes when you’re on vacation.  

Alternatively, you can place your potted tomato plant in a basin without submerging the roots. Water will enter through the drainage holes with the help of capillary action and keep your plant hydrated.

3. What happens when you overwater tomato plants? 

Overwatering causes root rot, yellowing leaves, and mushy fruits. Plants run on a calcium deficit when they are overwatered. Hydrated lime or ground limestone are fertilizers that can help in this situation. I wrote a detailed post on overwatering tomato plants and how to save them.

4. How do mulch tomato plants properly?

While mulching, leave a sufficient area around the plant’s stem for aeration and water absorption. Spread a 2-inch-thick layer of mulch after planting tomato trees for the best results.  

5. Do tomatoes grow well in the rainy season?

Tomato plants need plenty of sunlight and consistent watering. Light rainfall during the vegetative period can be good for their growth. To have a decent yield, the rainy season is not the best as it can lead to pest infestation, the splitting of the skin, overwatering, and excess moisture content of the soil.  

Bottom Line

I tried to answer the Internet’s most asked questions about watering tomatoes, signs of over and underwatering, and tomato growing best practices. Now you know how to water tomatoes properly and how much water tomato plants really need. 

Rest assured, following these tips will help you have the best tomato yield in years! 

One piece of advice before we go – is to avoid watering tomato plants directly above. This single technique will save your fruiting trees from pest attacks, premature evaporation, and multiple leaf diseases.