Managing Powdery Mildew
If you've grown zinnias, lilac, bee balm or phlox you've seen this, a white powdery substance on the leaves. This fungal disease is known as powdery mildew. It grows on leaf surfaces causing infested leaves to turn yellow, brown and eventually wither. The disease wont kill the plant it just looks bad.
So what can you do? Start with resistant varieties of susceptible plants like Garden View Scarlet bee balm. Grow plants in full sun and properly spaced for good air circulation.
If you decide to treat this disease, try one of the more eco-friendly products. Cornel University found mixing one tablespoon of baking soda with one teaspoon insecticidal soap or lightweight horticulture oil in a gallon of water works well.
Spray the Cornell mix or Neem, a plant derived fungicide, weekly. Start at the first sign of the infection and repeat as needed until the end of the season.
A bit more information: Reduce the risk of powdery mildew with a bit of spring thinning. Remove 1/4 of the stems of garden phlox, bee balm and other susceptible perennials back to ground level in early spring. This increases airflow and light penetration throughout the plant resulting in stiffer stems and often less powdery mildew. Or keep it simple and just cover up the unsightly leaves by planting slightly shorter mildew resistant plants around them. The surrounding plants mask the unsightly leaves so they do not detract from the beautiful flowers.
Related
Audio
Audio
Categories
Upcoming Live Events
& Webinars
March 27, 2024
FREE WEBINAR
How to Start a Garden for Beginners
Register now
April 3, 2024
Garden Trends
Franklin Public Library, Franklin, WI
April 10, 2024
FREE WEBINAR
Container Gardening Throughout the Year
Register now
April 11, 2024
FREE WEBINAR
7 Steps to Managing Water Where it Falls in Your Yard
Register now
April 17, 2024
Landscaping for Birds:
A Gardener’s Perspective
Glendale, WI
April 18, 2024
Be a Waterwise Gardener
Golden Rondelle Theater, Racine, WI
Register now
April 20, 2024
Pruning Hydrangeas and Other Shrubs
Pasquesi Home & Gardens, Lake Bluff, IL
April 27, 2024
Ridges & Rivers Book Festival
Viroqua, WI
April 28, 2024
Flowering Trees and Shrubs
Ebert's Greenhouse Village, Ixonia, WI
May 1, 2024
FREE WEBINAR
Ornamental Fruits and Vegetables
Register now
May 9, 2024
FREE WEBINAR
How to Plant Your Rain Garden
Register now
WATCH ON-DEMAND WEBINARS
Learn More