Why Does My Potted Plant Have Mushrooms? (With Gardeners Survey)

When I started growing potted plants and houseplants, I found mushrooms growing in some of them. I was curious to know why these mushrooms grow in the plants and if they could cause any harm to them.

Your houseplant or potted plant has mushrooms because there is good moisture and organic matter in the soil. This is a sign of good health of your potting soil because of the organic matter and beneficial organisms in it. The mushrooms reach the soil by the spores carried with the wind.

I’ve written details on where these mushrooms reach your houseplants and if they cause any good or harm. I’ve also written information to get rid of the mushrooms should you choose to do so.

Why does your houseplant have mushrooms?

Mushrooms grow in the potting soil because their spores have reached there and started growing. The spores could be present in the potting soil that you purchased. Spores are too small to be seen with the naked eye.

They may also reach the potting soil by wind. Insects, birds, animals, or even humans could carry the spores from outdoors to your houseplant.

But just having the spores in the potting soil will not cause the mushrooms to grow. The conditions have to be favorable as well.

**I asked gardeners if they had mushrooms growing in their houseplants. 46% reported that they did see mushrooms at some point when growing plants. And did not find them harmful to their plants.**

Most mushrooms require moist and humid conditions to thrive. So this may happen because you give plenty of water to your houseplants or potted plants.

Mushrooms are actually the “fruit” of a fungus that is infecting your houseplant. Occasionally, airborne spores may settle onto your houseplant soil, or you could carry them in from the outside environment. Sometimes, when repotting, we accidentally use contaminated potting mix. – Toby Schulz, CEO & Co-Founder @ Lawn.com.au

Mushrooms also need the right nutrients to grow well. They feed on decaying organic matter. They may thrive in your potting soil because of compost, mulch, wood chips, manure, or plant matter that is a rich source of such material.

They uptake nutrients and grow upwards. The cap is the last part of the mushroom to form. It springs open like an umbrella. Here is a cool time-lapse of mushrooms growing from start to finish.

When they produce a cap, the mushrooms release spores which are carried by the wind, and animals and insects that brush up against them. When the spores reach another nutritious medium they will grow into mushrooms and the cycle continues.

What are some common mushrooms that grow in houseplants?

Yellow mushrooms

This is probably the most common mushroom that grows in houseplants or potted plants. Because it favors the indoor warm and moist conditions. The scientific name of these mushrooms is Leucocoprinus birnbaumii.

The characteristic of these mushrooms are the bright yellow caps and the mushroom grows 2-4 inches tall.

Like other mushrooms, they thrive on the dead organic matter in the potting soil which means they will enrich the soil further.

Do note that these mushrooms are toxic to humans and animals. So avoid your children or pets from touching these. Or you can get rid of them if you think that’s the best choice.

The most common mushroom in houseplants is called Leucocoprinus birnbaumii. It has a yellow color. Its cap can be flat or roundish, depending on its maturity. – Vladan Nikolic, Founder and owner, Mr. Houseplant

Death Cap mushrooms

These aren’t very common, but they are found on the West Coast and the Northeast. They are small with a white stem, and a bowl-shaped cap. You will vomit after eating them.

Your internal organs will shut down and if untreated you will die. For full information about it, you should read this Wikipedia article here.

Galerina Marginata

This is a small thin and tan-colored mushroom that is found around the world. They have similar negative effects on the body when consumed as death cap mushrooms.

They are commonly known as funeral bells or deadly skullcaps. For the full description and identifying characteristics, you should read the Wikipedia article about it here.

Jack o’ Lantern

The Jack o’ Lantern is orange in color. It glows faintly a blue-green color when the light is low. You can see it if you look at it in a dark room.

This mushroom is not lethal but will cause cramps, vomiting, and diarrhea if you eat it. To see a detailed description of it you should read the Wikipedia article by clicking here.

Fly agaric

Also known by its scientific name Amanita muscaria. This mushroom is not deadly if eaten, but causes nausea, vomiting, diarrhea, and hallucinations.

It has a bright red cap with white spots. It is found throughout the Northern Hemisphere. When it is growing the cap is initially white, it then turns yellow, and then red. You can find a detailed description of it here.

Picture of oyster mushroom cultivation from my horticulture class

Are mushrooms good for potted plants?

Mushrooms are good for potted plants or houseplants because they decompose the dead organic material into nutrients.

Some people think that mushrooms take nutrients out of the soil and harm the potted plant or houseplant. But it’s the opposite situation because mushrooms put more nutrients back into the soil and help them grow better.

Mushrooms form a symbiotic relationship with other plants. They share nutrients with one another.

Beneficial mushrooms include those in the Basidiomycota family, which includes coral fungi, puffballs, false truffles, and bracket fungi. These types of mushrooms help plants by breaking down organic matter like dead leaves into nutrients for the plant to absorb. They also help protect the soil from erosion and keep it moist by slowing evaporation of water from the soil surface. – Stacie Krljanovic, Head Groundkeeper, Patio Productions

The fine mesh-like roots of mushrooms sit on the roots of your potted plants and excrete nutrients. The nutrients are taken up by your potted plant and it excretes its own nutrients which the mushrooms use.

Clumps of mushrooms also decompose what they are growing on. Whether it is fallen branches, dead leaves, or animal poop. Mushrooms break down organic matter and serve an essential part of the ecosystem.

The problem is that some mushrooms can be bad if consumed by humans or pets. And if you allow them to grow in the potted plants, you need to ensure they are not such mushrooms.

Are mushrooms bad for potted plants?

Mushrooms are not bad for your houseplants or potted plants but they can be bad for humans and animals.

The problem is that some of these mushrooms can be toxic if you touch them or accidentally consume them. They can be dangerous to your curious pets who may wander near the potted plants.

It is a good idea not to eat them unless you really know what type of mushroom it is. You should also wash your hands well after tending to your potted plants.

What is the best way to remove mushrooms from houseplants?

The mushroom caps spread the spores in the wind and grow more mushrooms. That’s why the first thing you need to do is remove the caps carefully.

You should use gloves or grab them with some paper towels to avoid contact with your hands.

You can then pull the mushrooms from the stem and put them in a plastic bag. Seal the bag and throw it in the trash making sure no one will touch them.

I would suggest also removing the top 2 inches of the potting soil where the mushroom mycelium will be growing. This may not completely remove all of them but help in slowing down regrowth.

The other method to get rid of mushrooms from your potted plants or houseplants is to use a natural fungicide. This will kill the mushrooms without harming your plants.

The important thing to remember about mushrooms is that they are just the reproductive part of the organism. The majority of a fungus lives underneath the soil for most of its life. By the time you get a recognizable mushroom, the fungus is well established. – Anne, Founder of Orta Kitchen Garden

Pro Tip: If you are using a planter box and found mushrooms in it, I’ve written a post on methods to get rid of such mushrooms.

If the mushrooms keep growing back, it’s best to get rid of the entire potting soil. Carefully remove the plant and keep it aside.

Sterilize the pot with a solution of 1 part bleach and 9 parts water. Apply the solution well inside the pot and leave it for an hour.

Then rinse the pot with clean water so that all the mushroom mycelia and spores are eliminated. You can now add fresh, sterilized, potting soil and put the houseplant roots back into the pot.

What are some natural fungicides that can kill mushrooms?

Tea tree oil. This an oil derived from a tree that is native to Australia called the tea tree. It has a strong pleasant smell. You can purchase organic tea tree oil at health food stores and the grocery store.

Citronella oil. This oil is derived from lemongrass. Lemongrass is a fragrant grass that has a sandpaper-like feel to the leaves. It can cause irritation when handled. It is often used in herbal tea and has a smell lemony flavor. Citronella oil can be purchased from health food stores and specialist online retailers.

Jojoba oil. This oil is derived from the seeds of the Jojoba plant, which is from Arizona, California, and Mexico.

Nimbin or Neem oil. Nimbin is extracted from the neem tree. A neem tree is also called a nim tree or Indian lilac and is native to the Indian subcontinent.

organic neem oil — Organic neem oil I use on my plants

Oregano oil. Oregano is a common herb which most people have heard of. The leaves are crushed and heated to extract the oil. Oregano is in the mint family and is regularly added to food as a garnish.

Rosemary oil. Rosemary is a fragrant herb that produces edible flowers. Similar to oregano oil the oil is extracted by crushing the plant. But, rosemary oil is only made from the flowers.

Milk. Milk has been shown to be effective in some cases of stopping mushrooms from growing. This is due to it creating a bad environment for mushrooms to grow. Though no formal studies have been done it’s worth a try.

How to prevent mushrooms from growing in houseplants?

Sterilize the potting soil

Spores in the potting soil are the most common way mushrooms reach your houseplants. So if you want to keep them away, sterilize the potting soil.

The simplest way to do this is to put the potting soil in the oven that is heated to about 200 degrees Fahrenheit for an hour. This will get rid of the mushroom spores.

Prevent overwatering the potting soil

You want to prevent moist conditions in the potting soil so avoid too much watering of the plants. Most houseplants don’t mind the soil dry before you water it.

So stick your finger 1-2 inches into the potting soil to check for moisture. You only need to water the potting soil if your finger comes out dry without any soil sticking to it.

Make sure the pot has sufficient drainage holes so the excess water drains out and does not remain for too long in the potting soil.

Remove unwanted organic materials

I recommend keeping your houseplants and the pots clean from debris. Mushrooms love to grow in the soil that has plenty of dead organic matter such as dried leaves, branches, flowers, and wood chips.

If you clear such material from the potting soil, it won’t give the mushroom spores the required substrate to grow.

Keep the houseplants in sunlight

Mushrooms prefer humid conditions to grow so keep the houseplants in sunlight at least for a few hours every week.

The heat will dry up excess moisture in the potting soil and prevent mushroom spores from growing.

Avoid overfertilizing the potting soil

Some mushrooms can thrive when there are excess nutrients in the potting soil. So make sure to fertilize only when necessary and the required amount.

Check the manufacturers instructions when using a slow-release or liquid fertilizer so you don’t go overboard.

Remove mushrooms as soon as possible

Once plenty of mushrooms develop in the potting soil, it can get difficult to get rid of them as they keep producing spores. These spores will also move to the other houseplants and grow mushrooms in them.

So it’s best to take them out as soon as you find the first sign of the fungal growth in the potting soil.

Conclusion

Mushrooms reach your potted plant when the wind carries their spores over. They will grow in the potted plant when the environment is favorable. They like the moist soil that is in a shaded environment and full of nutrients.

You need to remove them by using gloves or paper towels because some of them can be toxic. Or you can use essential oils that work as a natural fungicide to get rid of the mushrooms.