What causes white powdery stuff in soil?
When digging in a place where a shrub has been before, there is sometimes white substance in the soil. Does the soil then need any treatment?
Certified GKH Gardening Expert
It depends on what it is. Some white molds are beneficial, and some are not. Unfortunately, your photo did not come through, so I am unable to see it to ID it.
If you are concerned, you can apply a fungicide. This article will help: https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm