How to Cure Powdery Mildew on Tall Fescue

Powdery mildew infects grasses as well as plants and crops.

Tall fescue is a seasonal grass that is common in California. It can fall prey to a condition called "powdery mildew." Powdery mildew presents itself as a fuzzy white growth on the underside and tops of the grass blades. Powdery mildew is not only unsightly, it can kill tall fescue grass if left untreated. Fortunately, a few methods -- both organic and chemical -- can remove powdery mildew and return your tall fescue grass to a healthy condition.

Things You'll Need

• Sodium bicarbonate
• Skim milk
• Garden sprayer
• Sulfur or copper fungicide

Instructions

All-Natural Method

1. Mix 1 gallon cool water with 1 tbsp. baking soda. Alternatively, you can use a mixture of 9 cups water and 1 cup skim milk. Fill a clean garden sprayer with the mixture.

2. Spray the tall fescue infected with the powdery mildew. Apply the mixture thoroughly to all areas of the grass.

3. Repeat the process every 3 days until no more powdery mildew is present on the tall fescue.

Sulfur or Copper Fungicide

1. Spray a small, inconspicuous area of the plant with the fungicide and wait 24 hours. Examine the sprayed area of the plant for damage such as burning or wilting. If there is damage present, discontinue use of the spray. If not, continue with the rest of the procedure.

2. Spray the fescue liberally with the mixture. Spray in the morning on a warm day that does not exceed 90 degrees Fahrenheit.

3. Re-apply the mixture in the same manner as before 7 to 10 days after the initial treatment. Continue applying every 7 to 10 days until you have eradicated the powdery mildew.

Tips & Warnings

• Read and follow all directions on your specific fungicide's label.

References

• MyOrganicFlowers.com: Got Mildew? Get Milk!
• Cornell University The Plant Disease Diagnostic Clinic: Powdery Mildew
• Gardeners Supply Plant Care & Gardening Advice/Tips/Secrets @ HortChat.com: Powdery Mildew
• IGroHydro: How to Handle Powdery Mildew (PDF)
• Safer Brand: Powdery Mildew
• The National Sustainable Agriculture Information Service: Use of Baking Soda as a Fungicide