How to Stop Mushrooms from Growing Under Tomatoes

If you’re growing tomato plants, you might suddenly notice that you have mushrooms popping up in the soil underneath them. While the mushrooms are not a threat to the tomatoes themselves, they usually indicate that the soil or moist is wet.

Mushroom spores can live in the compost or mulch that you add to your soil. These spores can pop up when the conditions are right growing right next to your tomatoes.

Mushrooms are fungi blossoms, and they tend to blossom when conditions are moist and warm. Mushrooms growing near your tomatoes can be a a sign that something is wrong with the growing conditions. Check that your tomatoes might be showing symptoms of stress and see if there could be something up with your soil.

What causes mushrooms to grow under tomatoes

Here are the top causes why mushrooms grow under tomatoes and if you should be concerned.

If mushrooms are growing in the soil underneath your tomatoes it is a good time to check your plants. If you notice that the tomato leaves are rolling upward in a cupped position or even turning yellow there is likely to be a problem.

The mushrooms themselves aren’t causing the problem, but excessive moisture in your soil probably is. If you notice mushrooms in the soil, check the rest of the soil for any wet, water-logged spots.

Where to mushroom spores come from

If you added topsoil, compost or aged manures to your tomato garden, it likely that they had mushroom spores already in it. This is because a lot of commercial soils already have mushroom spores in them, and they’ll sprout when conditions are right.

Mushroom spores can also blow into your garden on the wind. They can also be carried with by the rain and washed into your soil.

It is a combination of correct weather conditions that causes your tomato plant soil to have a problem with mushrooms, but fortunately it is easier than you think to remedy the situation.

Do mushrooms harm tomato plants?

Mushrooms growing under your tomato plants will not cause any harm to the plant. They can be removed with a spade but remember that what you see above the ground are the fruiting bodies. The rest of the fungus grows under the ground, creating a network between the soil, plants bacteria and other fungi.

Mushrooms can appear after rain within a day.

Fungus will naturally occur in the ground and you will see the fruiting bodies or mushrooms when the weather conditions are right. Warmth, water or humidity can encourage the fungus to send up the fruiting bodies to reproduce. The spores from the mushrooms can travel through the air to other areas of your garden and appear somewhere else.

There are lots of natural fungus that exists in the soil that will naturally stay in balance with other fungi and bacteria.

How to stop mushroom growth under your tomatoes

Here are the top ways to stop mushrooms from growing under your tomato plants.  Take a look at each of these in more detail.

  • Make sure that your plants are properly spaced, which means that the plants themselves should be two feet apart and the rows should be four to five feet apart. The soil also has to drain well.
  • Try to raise the soil around the roots of the plants by several inches above your surrounding rows.
  • Water the plants two or three times a week in dry weather. Water deeply but make sure that you do not wet the stems and leaves of the plant.
  • When you water the plants, the soil should be moist but never soggy or wet. Place mulch around the base of the plants so that moisture is kept in without it puddling, which can be bad for the plants.

How to get rid of mushrooms under your tomato plants

If mushrooms have already started to grow in your tomato plant soil, here are a handful of solutions you can try:

  • Look for soggy spots in the soil so you can reduce the watering in those areas.
  • Your tomato plants will recover once the soil starts to dry, but if they start drooping, it means that they need a good soak, though not enough to create soggy areas in the soil.
  • If the mushrooms have already begun to sprout, simply pick them out with gloved hands or a small spade and throw them away. If you put them in your compost that can spread their spores and resprout in another area of your garden.
  • Try to dry out your soil as much as possible. Mushrooms can’t normally survive in dry conditions.
  • Make sure that there is good airflow and light penetration between your plants, which reduces humidity and allows sunlight to reach the soil. This is something that mushrooms don’t like.
  • Make sure that the soil around the plants is cultivated. Dig it lightly away from the root area to disturb the soil which will stop mushrooms from appearing.

You can also use a fungicide to get rid of the mushrooms. Remember that mushrooms are the fruits, so to speak, of the fungus and not a huge part of the entire organism. The mycelium, which lives within the organic matter in the soil, is your real problem.

But a good fungicide will penetrate the soil, treating the problem from within. You might have to apply the fungicide more than once, especially if mushrooms continue to pop up. In other words, keep an eye out for the growth of mycelium within the soil and the mushrooms above the soil.

When looking for fungicide treatments, you can choose between organic and non-organic types. You are safe using either one of these, but you have to make sure they are approved for use on food plants such as tomatoes. This way, the fungicide will be safe for both human and pet consumption.

What else can you do to avoid mushrooms growing under your tomatoes

Thinning and pruning your tomato plants will allow more sunlight to reach the soil which can stop the mushrooms from growing. Remove any leaf litter and other types of debris from under the tomatoes. Keep in mind that mushrooms generally thrive in the spring and fall, so wait for the summer sun to arrive and they will often die off themselves.


Finding mushrooms in your tomato plants doesn’t necessarily mean that there is a problem. It’s usually a sign that the soil is damp and the soil may not be getting enough light. Remember to give your tomato plants 6-8 hours of sunlight a day to help reduce the likelihood of mushrooms growing.

Once you know what to look for, it’s easy to watch out for the potential of mushrooms growing in your tomato plant soil, which means that you can figure out what to do about it quickly.

Happy growing.