Why Are My Tomato Plant’s Roots Showing? (How To Stop It)


If you grow tomatoes in your garden, it is possible that the roots will be showing on some of your plants.  But why does this happen?  I did some research to find out, and discovered a few possible causes.

So, why are your tomato plant’s roots showing?  Shallow watering of your tomato plants can cause the roots to reach towards the surface of the soil in search of water.  Your tomato plant’s roots may also show if you do not bury the plant deeply enough in the spring.  It is possible that wind, rain, watering, or flooding may wash away topsoil, exposing your tomato plant’s roots.

Let’s take a closer look at the each of the main causes of exposed roots and why they can be harmful to your plants.  Then we’ll offer some suggestions for ways you can treat tomato plant roots that are showing and prevent the problem in the future.

Why Are My Tomato Plant’s Roots Showing?

There are three main reasons that your tomato plant roots are showing: shallow watering, shallow planting, or soil erosion.  Luckily, there are steps you can take to address each of these causes of exposed roots on your tomato plant – we will get into this later.

tomato plant roots
If any of your tomato plant’s roots are showing above ground, then there is a problem!

Shallow Watering Of Your Tomato Plant

If you provide improper watering to your tomato plant, you can weaken the plant over the course of the growing season.  Even worse, the roots of the tomato plant may begin to show at the surface of the soil.

When you provide shallow, frequent watering to your tomato plant, the water never has a chance to penetrate deeper into the soil.  Either it evaporates in the sun and air, or the plant uses the water quickly.

water
Watering to frequently will encourage shallow roots on your tomato plants – they may even climb to the surface in search of more water.

Since there is no water to be found deeper underground, your tomato plant’s roots will not grow any deeper.  Instead, the roots will grow upwards towards the surface of the soil, where there is more water to be found.

Eventually, your tomato plant becomes dependent on frequent, shallow watering.  Missing a day or two of watering can cause a huge problem for the plant at that point.

If you continue to water frequently after the roots are exposed, the roots are more likely to stay wet for a long time.  This can lead to root rot, which can stunt the growth of the tomato plant, or even kill it.

When your tomato plant’s roots are showing, there is more likely to be a “feast or famine” situation.  Sometimes, the roots gets lots of water after a rain, and other times, the roots dry out quickly due to sun and air exposure.

Uneven watering can lead to blossom end rot, which causes a brown or black spot to develop on the bottom of tomatoes.

Blossom end rot is caused by calcium deficiency or uneven watering.

To avoid shallow and exposed roots, you are better off watering your tomato plants deeply and infrequently in the morning.  We will get into more detail on this later.

Your Tomato Plant Was Not Buried Deep Enough

Burying your tomato plant at a shallow depth at planting time in the spring is a mistake that can haunt you for the rest of the season.

Burying your tomato plants deep enough at the start of the season is one way to prevent exposed roots.

When your tomato plant is not buried deep enough, the roots may make their way to the surface quickly, especially if you have been providing shallow watering to your plants.

If your tomato plant is having serious trouble finding enough water or nutrients, you may see something strange happen.  At first, bumps will appear on the stem of the plant.

Then, the bumps will “sprout” into what look like short, greenish-yellow bristles.  If any of these bristles come into contact with the soil, they will become roots, called adventitious roots.

These adventitious roots will help the tomato plant to draw extra water and nutrients wherever they come in contact with the soil.  Of course, these roots will also show above ground unless you take steps to bury them under the soil.

If you have ever neglected to tie up a tomato plant to a support, you may have seen adventitious roots growing from the part of the stem that touched the soil.  You may also see adventitious roots (or their beginning bumps and bristles) on pepper plants, which are related to tomatoes (both are from the nightshade family).

For more information, check out this article from the University of Maryland Extension on adventitious roots on tomato plants.

Soil Erosion Due To Wind, Rain, Watering, Or Flooding

Soil erosion can occur in your garden for a variety of reasons: wind, rain, watering, or flooding.  Soil erosion will be worse if you have lots of bare soil where nothing is growing.

If soil erosion is severe enough, the roots of your plants, including tomatoes, can be exposed.  There are some steps you can take to prevent soil erosion.  These include putting up wind barriers and changing your water management practices (more on this later).

sprinkler
Don’t let the hose or sprinkler run too long in one place, or you can wash away topsoil from your plants.

When soil erosion occurs, you will end up losing not only the topsoil in your garden, but also any nutrients that it contains.  This makes it more likely that your tomato plants will be unable to find the nutrients they need to grow, even if you fertilized at the beginning of the season.

What To Do If Your Tomato Plant’s Roots Are Showing

We’ve talked about what causes a tomato plant’s roots to show.  Now it’s time to do something about it.  Here are some steps to take if the roots of your tomato plant are exposed and visible above the soil.

Bury Tomatoes Deep When Planting

One of the most important steps to avoid exposed roots is to bury your tomato plants deep in the ground when spring comes.  In fact, you should bury them deeper than you think.

When your seedlings are 6 to 12 inches tall, measure the height of each plant from the bottom of the root ball to the top of the main stem.  Then, find the point on the stem 2/3 of the way up the plant (1/3 of the way from the top).

tomato seedling
Measure your tomato plants and bury them to a depth of 2/3 of their height when planting.

Bury the tomato plant up to this 2/3 point, removing branches and stems below this point if you wish.  Make sure that you don’t damage the root ball when planting.

If you wish, you can plant each seedling in its own trench, at an angle.  For more information, check out my article on why and how to bury tomato plants deep.

Take Steps To Prevent Soil Erosion

Burying your tomato plants deep will not help if you lose lots of topsoil due to erosion.  However, if you take a few simple steps, you can prevent most of the soil erosion that will expose your plant’s roots.

First of all, put up wind breaks if you experience strong winds or storms in your area.  One common and aesthetically pleasing method is to plant hedges along the sides of your garden.

hedge
A hedgerow is one way to prevent soil erosion.

This helps to prevent wind from blowing away soil.  A hedgerow also does double duty by preventing soil from washing away in the rain (the roots of the shrubs help to retain soil by holding it in place).

For more information, check out my article on how to protect your plants from wind and storms and my article on how to prevent soil erosion.

Second, change your watering practices to prevent excessive water from running through your garden.  If you over water with a hose or sprinkler, the soil may wash away from the base of your tomato plants.

Instead, consider using a drip irrigation system.  Not only will it reduce soil erosion due to over watering, but it will cut down on water waste as well.

Finally, if your garden is subject to flooding due to rain, then make plans to divert water away from your plants.  You can do this by digging trenches and using pipes to direct water away from your garden, or towards plants that need more water.

If you find that you continue to have problems with flooding and soggy soil, check out my article on how to improve soil drainage.

If you want more information about soil erosion, check out my article on how to prevent soil erosion in your garden.

Cover Exposed Roots With Soil and Mulch

If your tomato plant’s roots are already showing, then it might be a good idea to cover them with some extra topsoil from elsewhere in your garden.  Make sure that the soil is just as good as what you would normally use to grow your tomatoes – this includes adding compost if necessary.

After covering the roots with topsoil, you can take the extra step of putting a layer of mulch over the soil.  If the mulch is heavy enough, it will help to prevent the topsoil from being carried away by wind or water.

wood chip mulch
Wood chips are one option for mulching over your topsoil.

Even if the mulch is not very heavy, you will lose mulch due to erosion before you lose precious topsoil.  You can use grass clippings, leaves, straw, wood chips, or even compost as mulch in your garden.

For more information on the pros and cons of each, check out my article on mulch vs. compost.

Water Deeply and Infrequently In The Morning

The goal is for your tomato plant’s roots to grow strong and move downward, deeper into the soil.  To encourage this, provide deeper watering at less frequent intervals.

When you water for a longer time period, the water has a chance to soak deeper into the soil.  This encourages a plant’s roots to go deeper underground to absorb the water.

Providing deeper watering in the early morning also prevents the sun from evaporating the water before it has a chance to soak into the soil and be absorbed by your plants.

sunlight through forest
Water your tomato plants in the morning for best results.

A larger, more extensive root system means that your tomato plant can draw water from further underground.  This helps the plant to survive periods of drought or especially hot days.

Most importantly, it will prevent the plant’s roots from showing above ground, preventing a whole host of other problems for your plant.

Conclusion

By now, you have a much better idea of what is causing your tomato plant’s roots to show.  You also know how to treat and prevent the problem of exposed roots on your tomato plants.

I hope you found this article helpful – if so, please share it with someone who can use the information.  If you have any questions or advice of your own about tomato plant roots that are showing, please leave a comment below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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