Skip to Content

How To Keep Mushrooms From Growing In Mulch

How To Keep Mushrooms From Growing In Mulch

If you are here, you have seen those little mushrooms popping up in your mulch. While it may seem pretty cool that you can grow mushrooms at first, once they start getting out of control, they may not seem so cool. Especially if these little squatters are hazardous to your kiddos or animals.

Fungi, a fancy mushroom category, gets its energy from decomposing organic matter to build itself. The decomposing organic matter is what you and I see as a mushroom. Don’t stress too much; you can kill the mushrooms without using any fungicide.

Types Of Mushrooms That Grow In Mulch

If you are curious as to what types of mushrooms typically grow in mulch, I have some answers for you. Several culprits that are known for intruding on mulch are the following:

  • Agrocybe praecox: spring agrocybe
  • Agrocybe Pleiades: common agrocybe
  • Coprinopsis atramentaria: tippler’s bane or alcohol inky cap
  • Lycoperdon pyriforme: pear-shaped puffball
  • Lysurus cruciatus: lizard’s claw
  • Pluteus cervinus: deer mushroom
  • Phallus impudicus: stinkhorn
  • Psathyrella candolleana: common psathyrella

Are Mushrooms That Grow In Mulch Poisonous?

This is a valid concern, especially if you have little kids running around that might try and see how mushrooms taste. Most fungi are harmless, particularly the wood-borne fungus that is the most common in mulched beds. However, a few types are poisonous or nausea-inducing if they are ingested.

The best safety measure for mushrooms of unknown type in your close vicinity is removing them. This will help give you peace of mind if you have little ones running around.

Why Are There Mushrooms In My Mulch?

There are several reasons why mushrooms are growing in your mulch. Generally, it’s because there has been a combination of fresh mulch, warmth, and moisture from recent rain or watering. This causes the perfect conditions for mushrooms to sprout up.

If you notice mushrooms in mulch wood, the wood chips have not been sufficiently processed to stop the fungus from growing. When the chunks of wood are processed, the mushroom spores are killed. These little stinkers will actually extend past the mulch and start putting their roots down into the plants or soils under the mulch.

Should You Remove Mushrooms From Mulch?

The easiest way to get rid of mushrooms with mulch is not with fungicide but with ingredients you probably have on hand. Vinegar mixed with water has been known to kill off these mushrooms. Follow this recipe:

  1. Mix 4 parts of water with 1 part of vinegar in a spray bottle.
  2. Cover any other plants or grass with a tarp or garbage bag.
  3. From about 4-6 inches away, spray the mushrooms with the vinegar water mixture.
  4. Wait for approximately 3-4 days for the mixture to kill the mushrooms.
  5. Once several days have passed, you are good to remove the dead mushrooms.
  6. Before you write off your mushroom problem, recheck to ensure all of the mushrooms are dead. If they are not, repeat the steps on the remaining mushrooms as many times as needed.

How To Prevent Mushrooms From Growing In Mulch

Mushrooms in Mulch

There are several different ways in which you can prevent the growth of fungi. Here’s a list of the following ways:

  • Use less mulch
  • Use compost
  • Prune or trim shrubs and trees
  • Rake mulch
  • Replace mulch

Use Less Mulch

It’s pretty common for mushrooms to grow when there is too much mulch. Using too much mulch traps the moisture in certain areas, creating the perfect conditions for mushrooms to thrive. By using less mulch, you will see the effects almost immediately.

If you have already placed your mulch, simply spread it to make it thinner. If this isn’t the reason, that is okay; it still good to keep in the back of your mind for the next time you are spreading mulch!

Use Compost

If you haven’t used compost, you should give it a shot. Compost can act as a solution for your mushroom issue in the yard. Mushrooms thrive in materials such as wood or bark-based mulch.

Compost doesn’t have the same properties as wood-based mulch. It is much harder for mushrooms to grow than their energy source is organic compost materials. The downfall to compost is that it doesn’t make your garden beds look as pretty.

Prune Or Trim Shrubs And Trees

One feature that mushrooms love is dark or shaded areas, as it helps them grow faster. Trees or shrubs can create areas of darkness for the fungi to grow. In areas with overhanging trees and dampness, it makes the perfect conditions for mushrooms to pop up.

The fix for this is relatively easy. Make sure you keep your shrubs or trees trimmed up to help prevent the dark areas in your yard.

Rake Mulch

Surprisingly, running a rake over your mulch can make a big difference. When you rake the mulch, it aerates it, causing it to dry out. When you dry out the mulch, it prevents the mushrooms from developing deep roots.

Raking will also help your plants, as it will help the plants breathe easier. It also helps prevent them from suffocating from all of the moisture.

Now with this being said, you don’t need to go and rake every single day; it would be a waste of your time and energy. However, raking once a week would be highly beneficial!

Replace Mulch

If you have tried the options above or do not think these will fix the mushroom problem, replacing the mulch is always an option. It might be even more effective for your entire landscape to replace the mulch. One random tidbit that might help is adding lime to the soil; mushrooms aren’t a fan of acidic environments.