What is the White Stuff in My Soil?

Whats the white stuff in my soil
What’s in the soil?

Lately I have had many queries about what looks like white stuff in the soil of various gardens. I have seen it in my vegetable gardens when harvesting vegetables. Its very common and isn’t a bad thing so don’t panic. Its called mycelium. Its a typical fungus made up of tiny threads called hyphae. I know another foreign word. Stay with me, its not that complicated.

Whats the white stuff in my soil
White threads fill the soil

When you look at the white stuff in the soil, grab a magnifying glass. The threads or hyphae branch out in all directions throughout the soil. Fungi are found primarily in aerated surface layers rich in organic matter. Its often seen when harvesting vegetables.

Whats the white stuff in my soil
What’s in my soil?

If your soil is rich in organic matter, often you will see mushrooms develop from the mycelium. Mycelium will always be present in the soil as long as there is nutrients available. It is said that mycelium is the Internet of the soil bringing connections to all living matter.
There is also a lot of bacteria in the soil. When I tell children that they step back as if its something to be afraid of. When I tell them that its good bacteria they don’t understand. We have brainwashed our children to think that all bacteria is bad and it just isn’t so. Estimates range from 10-100 million bacteria exist in one gram of soil. We need bacteria in the soil as they act as decomposers.
Bacteria and fungi are not the only things living in our soils. We also have algae and actinomycetes. Algae are often found on poorly drained soils and live near the soil surface. Actinomycetes, I know another big one, are widespread in the soil. They are involved in the decomposition of organic residues in the soil. They do best in soils with a PH over 5.  Did you know that many of our antibiotics are produced from actinomycetes?
So there you have it, lots of microorganisms occupy our soils. We just can’t see most of them as well as the mycelium. Don’t forget that we also have an animal population in our soils as well. From nematodes to protozoa, earthworms and insects, there is amazing life happening right below our feet.
So next time you walk over your garden, tread lightly. Treat the soil right by growing organically. There is life below there that should be treasured.

27 thoughts on “What is the White Stuff in My Soil?

  1. I’ve noticed this before and didn’t know how to go about finding out what it was. Thought it might be leftover root product from plants.

    I recently read about mycelium being used to make compostable product packaging, so it’s doubly interesting to realize it’s something growing in my own backyard. Thank you!

  2. ihave this all through my garden but nothing is growing, and clumps of mushrooms which have rock hard roots surround the base of all my plants. the layer is about 2 inches below the surface and about 4inches thick.

    1. It sounds like you may have too much organic matter in your soil. Mushrooms tend to grow at certain times of year when conditions are perfect. Have you taken a tree down? Often as tree roots decay mushrooms grow in the area.

  3. Our mold is under the surface an is a thick layer. My husband is putting another drain in thinking it was from sitting water. Do I have to remove all this mold and soil to start over? The mold is whitish gray and clumped but breaks up easliy.

    1. I am not sure without seeing your soil first. Our garden has a lot of sitting water during winter but I haven’t got thick layers of mold, just heavy clay soil. Mold is very different than the normal mycelium seen in soil. It will be interesting to see if the mold disappears once your soil dries out.

  4. Hi,
    This morning I noticed a copious amount of white (mold) or (fungus) around one of my dill plants. It covers around the plant and looks as if a volcano erupted around the dill. Do you have any idea what to do for this? My husband made raised beds for my flowers,except everything in them are vegetables. Funny! Thank you and I enjoy reading your information.

    1. Diane, Why not plant flowers around the edges of your raised beds with your vegetables. I would remove the mold from the dill but its spores may remain. Warm humid conditions can cause mold to form in the garden. Be sure to give your plants good air circulation by allowing them proper spacing.

  5. I am wondering how to distinguish between the good mycorrhizae & ‘white fungus’, which is not-so-good.
    Most every article or blog I’ve read today declares it’s 1 or the other.
    Thoughts? Thanks!

    1. Hi Jo, I find the mycorrhizae is usually located where you had removed plants the previous season. I tend to cut off the plants at soil level as roots will decay on their own. Often thats where I see the hyphae in the soil in the early spring when starting to work in the garden.

  6. I’ve found this white musty smelling stuff in my soil too. I only find it when I’m digging. I do compost but not usually where I find this white substance. I find it sometimes where I also find ants but not all the time. There is a walnut tree root growing around there but not in all places that I find it. I’ve found it in the most sunny locations and not so sunny locations. It’s very localized and doesn’t spread. I haven’t noticed any mushroom growth. I took a couple pictures and hoping to add them to my comment or I can email the picture to you

    1. Hi Deana, I would recommend getting a soil test is it smells musty or doesn’t look right or you could take a soil sample to your county extension to look at.

  7. Thanks for the info! I was worried after checking on some seedlings today and finding a powdery white/moldy like substance on the surface of the topsoil. I’m still debating removing it, but you eased my panic by reminding me that mycelium are a part of a healthy plant environment.

    1. I hope your seedlings are fine. Overwatering can cause mold and algae to form on the soil surface of seedling beds so check to be sure this isn’t your issue.

  8. thank you. very interesting and well written in an easy way to understand. I am going to take a microscope to my garden to check those little yellow guys out. To me it looks more like a grey powdery substance in my garden… more grey than white… might it be different? Is it a good idea to spread it around in the garden area (if it is good for one spot – why not the rest) Also, why is it just in certain areas of the garden… is it working it’s way around to eventually being a larger amount of it’s self? 🙂

    1. Hi Cathy, take a sample into a local extension office or soil lab for an answer. Everyone has different soil and different bacteria so its difficult for me to answer your question without seeing it.

  9. Hi we have the same white mould in our lawn – in the areas this is the grass has stopped growing . Is there anything we can do to get rid of it ?

    1. John I would recommend getting a sample of what it looks like and taking it to your county extension office to see if they can identify it. This mycellium grows everywhere and shows up where trees may have been removed as well as in gardens. Normally this fungus is not a bad thing so its best to consult with an expert in your area.

  10. I have potted impatiens on my deck this summer. There are silver threads on the service of the soil. It almost looks like fish wire but you can’t pick it up. Whatever it is it is killing the plants. Typically, I throw the plants in the woods before winter. I want to make sure whatever is killing the plants doesn’t start killing the vegetation in the woods. Any idea what it is?

    1. I would take a sample of the soil to your county extension or master gardeners to see if they can identify the problem. Impatiens are prone to downy mildew.

  11. It is very difficult not to “overwater” in southern Louisiana where we have a lot of rain, and this season tropical depressions. Is there a way to control the mycelium if this is what it is on top of my vegetable bed and also underneath the soil where the old veggie roots were? I’m trying to prepare the bed for fall crop planting between rainstorms.

    1. It shouldn’t be a problem. We get 165 days of rain each year and it’s never been an issue. Are you tilling the garden for fall as the mycellium prefer a no till system of managing the soil. Its a good thing to have in your soil as it feeds plants nutrients and the plants return the favour.

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