The Bottom Line: How Deep Do Tomato Roots Grow?

Tomato Roots

How deep do tomato roots grow? You must know how deep tomato plant roots go into the soil if you intend to grow your tomato plants in pots or a raised bed garden or if you need to transfer your tomato plants and want to avoid injuring their roots. Continue reading to find out how far down your tomato plants’ roots extend.

Freshly planted tomato plant

How Deep Do Tomato Roots Grow?

How deep are tomato roots? Tomatoes have a taproot system because they are dicots, plants with two cotyledons and embryonic leaves. In contrast, monocots—plants with only one embryonic leaf—have a fibrous root structure. 

When you think of a plant’s roots, you typically picture a network of several small, branching roots that resemble the upside-down branches of a tree. This is a fibrous root system. In contrast, a taproot system contains some tiny, branching roots, but the taproot itself is directly in the middle. 

The taproot is deeper than the other supporting roots and is larger so that it may take more water and nutrients from the soil. A taproot will dig a straight tunnel into the ground if there are no obstructions in its path.

A tomato plant’s taproot can reach a depth of 3 feet (0.9 meters) in the ground. When a plant needs to go farther to receive water and nutrients, it needs to grow healthy and strong; long taproots like this one are especially likely to sprout. Because of this, tomato plants that develop in poor, loose soils have the longest taproots.

How Big Does a Tomato Plant Get?

They typically measure between 6 and 20 feet (1.8 and 6.1 meters). They do not stop flowering or producing fruit before a heavy winter. They need sturdy stakes or cages and typically a lot of pruning to keep them in check. 

They require a lot of room. They will topple over on each other or out of bed completely if you plant them too tightly together. They will cover many of their tomatoes and decay behind mounds of plant cover. The majority of heritage tomatoes are indeterminate.

How Deep Do Tomato Plants Need to be Planted?

More than 24 inches (60 centimeters) of soil can support tomato growth, but not less. The basic planting depth for tomatoes is 12 inches (30 centimeters). Only a taproot measuring one foot (0.3 meters) in length can develop on the plants. Thus, you will need to provide additional support.

How Deep Should My Raised Bed Be?

You will get relief to learn that merely 1 foot (0.3 meters) is necessary if you are seeking a quick answer since you are building a raised bed or if you want to know if your existing raised bed is deep enough for tomatoes.

You’ll note that I said adequate rather than excellent. In general, tomato roots can develop between 2 and 3 feet (0.6 and 0.9 meters), though around 2 feet (0.6 meters) is more typical; hence the ideal depth would be greater than 2 feet (0.6 meters).

Why You Should Plant Tomatoes Deeply

You may ask, how deep do cherry tomato roots grow? Cherry tomatoes need deep planting. You should put most plants in a hole bigger than the pot they came in. Tomatoes are an exception to this rule. Yet why?

Everything is in the Roots

There are accidental roots in tomatoes (roots that form from non-root tissue). This indicates that they can expand their roots along their stems wherever they bury the stem. Therefore, it is advisable to bury the plant deeply to grow a bigger, stronger root system along the stem.

The tomato will be able to absorb more nutrients and water if there are more roots present. The additional roots strengthen the plant’s soil anchor and help it maintain its erect position in the face of the wind. 

Burying most of the plant will shield it from early spring frost and cold weather after planting. All of this will result in a tomato plant that is larger, stronger, and more fruit-bearing.

Young tomato plant in the garden

Factors That Determine Tomato Root Depth

You must be aware of the factors that restrict tomato plant root depth. Let’s examine each of them individually.

Tomato Variety

You can distinguish the determinate and indeterminate kinds of tomatoes from one another. The latter grows through the growth season, whereas the former grows until it reaches a specified size. For instance, many of the well-known heirloom tomato cultivars are indeterminate.

Because they, like the foliage, continue to grow throughout the growing season, provided that other variables do not impede this growth. Indeterminate types have further roots and taproots that penetrate deeply into the soil. You can even grow indeterminate tomatoes in pots.

Depth of the Container

The depth of the pots or containers that tomatoes are grown in naturally restricts their ability to grow. Even if your container was 18 inches (45.7 centimeters) deep, it is common to see the taproot makes circles around the base of the container when you uproot the plants after the growing season. When transplanting young plants or seedlings, you could also notice this.

However, if you plant in a raised bed, the depth of the bed is sometimes equal to the depth of your container because the soil beneath the bed is frequently impenetrable hard clay or simply soil that has never undergone tilling. The roots of your tomato would undoubtedly extend past the raised bed’s edge if necessary if the soil quality beneath the raised bed is good.

Soil Structure

Even though tomato plant root, in general, is tough and can squeak into even the smallest cracks, there are some instances where the soil is too compact, and root growth is impossible. The root of your tomato would continue to develop after it reaches this layer, but laterally, exactly like it would at the base of a container.

Soil Quality

The word “soil quality” refers to the soil’s nutrient content. In general, roots seek out nutrients and water as they grow. Tomato plants grown at home get a lot of attention and don’t have to expand their roots too far in search of nutrients. The roots would continue to expand significantly but very differently than if placed in unfavorable soil. 

In healthy soil, secondary roots would receive a lot of energy, which would delay the taproot’s growth rate and reduce the root system’s overall depth towards the end of the growing season. This closely resembles a tomato leaf, which grows densely in conditions of adequate light but grows long and stringy in those with low light. Read our article and find out the Best pH For Tomatoes.

Planting Technique

Tomatoes differ from most plants because they can tolerate having their stems underground and even benefit from deep planting. You should remove the lowest leaves (up to 2/3 of the plant) off your tomato plants a day before transplanting them and let the wound heal. Put the stem that is now bare in the ground.

Tomato plants can develop roots from their stem, which enables them to acquire more nutrients and grow taller without support (similar to a house with a deep foundation) (the original root system is deep into the soil). 

The Tomato Root System Explained

Because tomatoes have two cotyledons or embryonic leaves, they are dicots (the first leaves that appear from the seed). The existence of a taproot system is another characteristic shared by dicots.

A taproot enables a plant’s root system to delve deeply into the ground, and subsidiary roots that sprout from this main root help the plant take up water and nutrients from the surrounding soil. If there are no obstructions in their path, taproots will fall straight down.

Due to their taproot system, tomatoes have deep roots extending as far as 3 feet (0.9 meters) under some circumstances. The plant seeks water or nutrients in poor, loose soil.

The optimal root length would supply enough water and nutrients for the plant’s structure. Tomato types require additional assistance in addition to a strong root system. There needs to be equilibrium. 

How to Plant Tomatoes Deeply

Measure and Prepare the Plan

To fully utilize those accidental roots, you should bury around two-thirds of your tomato plant, including the primary root ball. The size of the trench or hole you dig depends on the height of your plant. Before planting, measure the plant to ensure the hole is large enough; it’s probably deeper than you believe.

When the seedling reaches a height of between 6 and 12 inches (15.2 and 30.5 centimeters), it is the ideal moment to bury the tomato plant. It is not necessary to remove the lower leaves and stems; you can bury them with the rest of the plant. 

Nevertheless, depending on the size and shape of your transplant, you’re welcome to remove them if doing so helps facilitate planting. Removing leaves from the plant, don’t snap the primary stem.

Prepare the Soil

Verify that the soil is neither compact nor hard. Deep planting will be useless because the new root system won’t be able to grow into and through compacted soil. To prepare and loosen your soil, apply additives like compost (the additional nutrients won’t hurt either).


When planting tomatoes in the ground, there are two techniques to choose from: the trench method and the deep hole approach.

Deep Hole Technique

Although the deep hole technique is the most popular, it can be challenging in dense soil. The hole must be deep enough to bury most of the stem, which extends up to just below the top set of leaves.

When the primary root ball is present, this should represent roughly two-thirds of the plant. Place the plant in the hole after gently loosening the roots, and then fill it with soil till the soil line.

Trench Method – Planting Sideways

If your soil is a bit too heavy or if you are unable to dig a hole deep enough to fit the entire tomato plant, the trench approach is appropriate. Additionally, the warmth of the upper soil along the stem has the extra advantage of promoting rapid development.

The trench has to be roughly 6 inches (15.2 centimeters) deep and two-thirds the height of the tomato plant long. Fill the space surrounding the stem with soil as you lay the tomato plant on its side at a slight inclination, exposing the top leaves.

Please do not worry that the exposed portion of the plant is not erect; as the stem receives more sun exposure, it will quickly move upward.

Place Supports

Depending on the type of tomato you are growing, you might need to add support to the plant to help it stand straight. Early support placement will assist prevent root disturbance in the future. Carefully place a cage or stake close to the root ball to avoid harm.

When planting in a trench, you can either wait until the plant is upright before adding supports like cages or attach a stake next to the horizontal stem and wait for it to straighten out before tying it to the stake. This will stop the main stem from possibly snapping, which could harm or kill the plant.

Water Thoroughly

After planting, water slowly and thoroughly. To get the most out of planting tomatoes deeply, stimulate roots to grow and expand downwards by giving them a lot of water. Water your plants frequently throughout the growing season to maintain a robust, healthy root system.

Deep planting could be counterproductive in the world of backyard gardening. On the other hand, your plants will appreciate it when it comes to tomatoes. Your plant will expand and get stronger due to the extended root system, producing a fruitful and mouthwatering harvest after the growing season.

Possible Issues Associated With Deep-Rooted Plants

In some circumstances, you might want to make an effort to keep your tomato from sinking too far into the ground.


Once the risk of frost passes, most people plant their tomatoes. Because tomato plants prefer warm soil, it is not a good idea to plant deep into the ground once the top half defrosts. This wouldn’t be a problem, although growth would be slower, and fruiting might happen a week later. Read our article and find out What Temperature Is Too Cold For Plants?

Impermeable Soil

The inability of your plant to establish roots through impermeable soil is not an issue at all, but if water cannot flow through either, you will constantly soak up the roots. This may result in problems like root rot. 

Even if the problem may not propagate to the root system, it is still something you should avoid—knowing how to correctly water tomatoes is a crucial skill that helps with many concerns.

Clayey Ground

Compared to sandy/grainy soil, clayey soil tends to hold water for longer. This is not a problem if your plants get accustomed to it and grow in it regularly. But there are times when this can be an issue. 

For instance, you must not water a raised bed where tomatoes grow so that water seeps into the ground below. However, a heavy shower near the end of the season can cause ripening tomatoes to split because of the rapid rush of water into the fruit if you have clayey ground below the bed and if your tomato roots get into it.

Tomato plants

The Final Say

Amateur gardeners frequently make the error of concentrating just on robust stems and leaves while completely ignoring the base. You can get a lush top if you focus on developing a strong root system, and the soil can support a healthy plant. The phrase “feed the soil, not the plants” is popular in the gardening community and applies to all sorts of plants, including tomatoes.

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