Radio Transcript
July 24th, 2026
Tanner Collier

Hello, this is Tanner Collier, the Horticulture Agent with Burke County Cooperative Extension. Our program today is about “Powdery Mildew.”

As you walk through your flower or vegetable gardens, have you ever seen white, powdery spots on the leaves of your plants? This is powdery mildew. Powdery mildew is a fungus that affects various types of plants, from crape myrtles and roses to squash and cucumbers. It starts as spores that float through the air, and they thrive in high-humidity environments. Powdery mildew is at its peak when day temperatures are warm and night temperatures are cool. You might be asking, “Will this make my plants die?” Typically, powdery mildew will not kill the plant, but it does affect the appearance and yield of it.

There are several cultural practices you can use to help prevent powdery mildew from forming. Proper plant spacing, increasing airflow through pruning, and avoiding excess water on foliage will help reduce humidity and, in turn, reduce powdery mildew. You can also select powdery mildew-resistant plants to put in your gardens. If you see powdery mildew on your plants, remove the infected parts and discard them. Be sure to remove all infected tissues from your garden because powdery mildew can overwinter. Fungicides can be used to protect healthy plants from powdery mildew, but they have little curative action. Make sure you read the label on the fungicide and follow the instructions. Remember, THE LABEL IS THE LAW!

This has been Tanner Collier with Burke County Cooperative Extension. If you have any questions or want more information, you can contact us at (828) 764-9480.