Does Powdery Mildew Stay in the Soil?

Powdery mildew spores primarily live on plants, but can also survive or overwinter in soil, compost, mulch, or other plant debris. The spores spread from plant to plant (or, are initially introduced into your garden) by wind, insects, splashing water or direct contact from infected plants.

Does powdery mildew contaminate soil?

While powdery mildew does not typically kill a plant, it will irrevocably discolor and disfigure the buds, blooms and foliage that it infects. Soil controls are mostly cultural and revolve around keeping the soil from being splashed up or carried up onto tender plant tissues.

Can I reuse soil after powdery mildew?

Remove all obvious plant debris and a couple of the top inches of soil that may have minute bits of debris in it. Send that to the landfill. You can use the rest of the potting soil elsewhere in your landscape, but do be careful to wash and disinfect your pots before reusing them.