This year I started a large perennial garden. I live in northern Wisconsin. The soil is very loose and seems like great soil. Some of the soil came from the top layer of soil in a cow pasture. I started getting this white fluffy fungus on the soil. I'd shovel it out and in a few days have more in different spots starting up. I'm suspecting it's coming from the cow pasture soil because I still have a pile not used yet and it's starting to grow the white stuff. A plant person told me to try a mixture of baking soda and epsom salts and water. It seemed to work on the spot I'd put it on but spots keep popping up anywhere and everywhere. It is in the open and gets sun part of the day, so it doesn't stay wet. I'm not sure what to do.
White Fluffy Fungus in Outdoor Perennial Garden
Certified GKH Gardening Expert
I may be that the soil or manure was not composted down enough.
I would treat the plants with Neem Oil. This works as both an insecticide and fungicide.
It is safe for people, pets and bees.
This can also be caused by damp conditions and lack of air flow.
Make sure the soil is not over watered.
I would remove any large amount of fungus that you can see. Likely with drier conditions and the Neem Oil your soil will improve.