Spring Garden Tips
Managing Powdery Mildew

Tips for dealing with the fungal disease powdery mildew.

Quicktime media Quicktime Windows Media Video Windows Media

JavaScript is disabled!
To display this content, you need a JavaScript capable browser.


powdery_mildewIf 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 won’t 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 ¼ of the stems of garden phlox, beebalm and other susceptible perennials back to ground level in early spring. This increases air flow 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 Garden Moments

Attracting Beneficial Insects to Your Garden

Join forces with nature and increase garden productivity while keeping garden pests under control.


Botrytis Blight on Peonies and Roses

Brown buds that fail to open on peonies and some roses, especially the white and pink flowered varieties are likely the result of Botrytis Blight also known as Gray Mold.

View Gardening Video...

Controlling Creeping Charlie in the Lawn

It’s fragrant, produces purple-blue flowers in spring, and adapts well to sun or shade. I just described creeping Charlie (Glechoma hederacea) also known as ground ivy, a weed most gardeners are trying to eliminate from their lawns.

View Garden Video...

Eco-friendly Control of Aphids in the Garden

Ants, lady beetles and a clear sticky substance on your leaves are good indications that aphids have moved into your garden for a meal.


Eco-Friendly Disease Control

Prevent disease problems with proper plant selection, care and clean up.


Eco-friendly Lawn Care

You can have a lawn and still be kind to the environment.

View Lawn Care Video...

Eco-friendly Mosquito Control

Don’t let mosquitoes prevent you from enjoying your garden this summer. A fan and a bit of outdoor housekeeping will help you manage these pests.

View Gardening Video...

Eco-friendly Spider Mite Control

Hot dry weather is hard on you and your plants but great for many pests.


Eco-friendly Whitefly Control

When fall arrives I can’t seem to resist taking a few plants in for winter. Unfortunately, a few whiteflies often try to hitch a ride in with the plants.

View Garden Video on Eco-friendly Pest Control...

Garden Pests - Managing Japanese Beetles

Strategies for dealing with Japanese Beetles

View Garden Video...

Holes in Hosta Leaves

Holes in hosta leaves – a common sight no matter where you garden.


Mowing Your Way to a Healthy Lawn

Mowing the Lawn

View Garden Video...

Recyclables Find New Life in the Garden

Plastic and Glass Containers Crafted into Useful Garden Tools

View Garden Video...

Water Conservation Never Looked So Good

Beautify Your Rain Barrel

View Garden Video...

Waterwise Gardening Tips

No matter where you live, being a waterwise gardener makes environmental and economic sense. And it’s really easier than you think.