A great question came in this week to Ask Gardenerd:
“My garden soil has this yucky whitish hue to it. I am assuming it is a type of mold (I do think I have been overwatering). When I took it out of the bags (10 bags)a few months ago, it did have a few “moldy”looking spots (I took back some of the bags but they told me it was”normal”). Is there any way I can salvage this soil?”
I understand your concern, but the folks at the nursery are correct. The mold in your soil is totally normal. Most good quality soil amendments have beneficial micro-organisms present that help your soils “social life” so to speak. Here is what Kellogg has to say about it (they make my favorite soil amendments).
“The mold you see, although it may look alarming, is harmless and an indication that the material is rich in plant nutrients. The white fuzzy “mold” is actually from a mycelium fungus which is a naturally occurring beneficial soil fungus that grows in rich organic matter.
Simply place all the soil from the bag in a wheelbarrow or in pile on the ground and stir it up with a rake or shovel. The white fuzzy stuff will mostly vanish from sight. It will not harm your plants- it will actually help feed them. This type of fungus helps break down the good stuff like worm castings, kelp meal, bat guano and chicken manure making these available to plant roots.
These pores of the fungi are present in the compost all the time. This is normal and good. Certain combinations of temperature, moisture, air and organic material can make the fungi grow unusually fast which is apparently what happened to the bag at your house. Not to worry. Simply work the compost into your garden soil as instructed on the package and the plants in your garden will love it.“
If you are seeing mold or mushrooms in your garden where this soil is located, you may be overwatering. You can cut back on watering and that should help eliminate the visual signs of mold and mushrooms. You can also keep loosening the surface layer of soil around your plants to help air flow properly. But don’t worry, it’s totally okay to have this friendly fungus co-habitating with your plants.
Thanks for writing in!
Thank you for this site. Bookmarking it for future. I haven’t time to look around much and am wondering what u think about hydrogen peroxide …3% solution to help soil?
I am not a fan of using things like hydrogen peroxide or baking soda to solve plant and soil problems. Best to build up the right fungi and bacteria with compost, compost tea and worm castings and let nature do her thing. We get in our own way so much that we make it worse.
no pix, sigh
Sorry, Bill. This is a very old article, before photos were important in blog posts. Perhaps we’ll update it some day.
Thank you for the info. I live in a swampy area and the shady area of the yard has little grass. It does have moss and not a few mushrooms.
This fuzzy stuff has suddenly started appearing on mushrooms past their prime and tree roots that are exposed (most got whacked by the mower).
I had put some of the moss in a terrarium (before I saw the white stuff), which now has a fuzzy white spot. I also had put in a little lichen from a pear tree in the yard.
I think the terrarium is too wet, so will let it have some air to see if that helps a little.
Yep, sounds too wet. If you can add compost and mulch to that swampy area, it will help break up the soil a bit and improve drainage.
Thank you for the advice I have been working hard and one says you have to dig it out and put new in destory all the pla tsand I have a mold allergy
I have white powdery mold in my outside veggie garden, smells a little like ammonia, what to do to get rid of it?
It’s probably just mycelium and nothing to worry about. You want populations of beneficial fungi in your soil. If its appearance bothers you, scrub it off with a brush and maybe some vinegar, but otherwise I’d leave it alone. You can break up the soil a little bit to disrupt it, and reduce watering (mushrooms appear in excessive moisture).
Thanks for this information! I found this in my newly built (3 weeks ago) raised veggie/herb/marigold bed. I was worried before reading the responses!
Glad we could help, Patricia. Happy gardening!
I wasn’t aware that molds are harmless i always thought they were harmful.
I figured that mold would be a good sign of fertile soil. Granted I wouldn’t want to grow fruits or vegetables near it, but I’m glad to know it’s good for your garden. Thanks for sharing this helpful tip!