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