• slide
  • slide
  • slide
  • slide
  • slide
  • slide
  • slide
  • slide

Managing Powdery Mildew on Bee Balm

If you’ve grown bee balm you probably know about powdery mildew. This fungal disease produces a powdery white film on the leaves. This prevents sunlight from reaching the leaves that can eventually yellow and brown. Fortunately, you can reduce your problem with proper selection, siting and spacing.

Start by selecting powdery mildew resistant varieties whenever possible. The North Carolina State University found Claire Grace, Marshall’s Delight and Stone’s Throw Pink were most resistant early in the season. Marshall’s Delight continued to show good resistance later in the season along with Blue Stocking, Cambridge Scarlet, Elsie’s Lavender, Mahogany and Vintage White.

Reduce problems on existing plants by growing them in full sun. Give the plants plenty of room to increase air circulation and light reaching the plant. Improving the growing conditions can help reduce disease problems.

A bit more information:  Further decrease the risk of powdery mildew with a bit of spring thinning. Remove about ¼ of the stems in early spring to allow more air and light to penetrate the plant. This will encourage sturdier stems and discourage disease problems.

Upcoming
Events & Webinars


August 6-16, 2026
Wisconsin State Fair
We Energies Energy Park, West Allis, WI

August 29, 2026
Composting 102
Milwaukee Public Library - East Branch
Register here

Sept. 3, 2026
FREE WEBINAR: 
Tree Planting and Care
Register here

Sept. 11, 2026
Illinois State Master Gardener Conference
Rockford, IL
Register here

Sept. 12, 2026
2026 Knowledge in Bloom Conference
Urban Ecology Center, Milw., WI
Register here

Sept. 17, 2026
FREE WEBINAR:
Fall Landscape Care and Planting

Register here

Sept. 26, 2026
Pruning Hydrangeas & Other Shrubs
Pasquesi Home & Gardens, Lake Bluff, IL

Oct. 6, 2026
Upper Midwest Invasive Species Conference
La Crosse, WI
Register here

WATCH ON-DEMAND WEBINARS

MORE UPCOMING EVENT DETAILS 

Book an Appearance

Learn More

Sign up for Melinda's free newsletter for a chance to win this Milorganite 100th Anniversary prize package.

ENTER NOW