If you garden long enough, sooner or later you'll find yourself dealing with powdery mildew problems. This common fungal disease can affect virtually all types of plants. Fortunately, other than slowing down growth, reducing yields, and looking terrible, it rarely kills affected plants. Here are some ways to tackle the problem organically.
There are many types of powdery mildew, all of which spread by microscopic spores. These spores can live for years in leaf debris or in the soil, and are carried to plants by wind, insects, and splashing water. Conditions that favor the spread and growth of powdery mildew include a lack of air circulation around plants (especially in the shade), dry weather, and temperatures between 60 and 80 degrees F.
Spray a fresh batch of the mixture on the tops and bottoms of leaves every 7 to 10 days. Because oil combined with the heat of the sun can damage plant tissues, it's wise to test the solution on a few leaves before using it in large quantities.
Water: This low-tech approach must be done consistently to work effectively. Unlike indoor mildew, powdery mildew hates water and spreads readily on dry leaves. The spore plugs must embed themselves in leaf tissue to grow, which they can't do on slippery, wet leaves.
Spray down the leaves with the garden hose daily. Make sure you do this early enough in the day so that leaves dry out before evening, otherwise you'll be swapping one fungal disease for another.
Compost Tea: When used as a foliar spray, compost tea has both insecticidal and fungicidal properties. Place a gallon of well-aged compost in a 5-gallon bucket and fill it with water. Stir well and let sit in a warm place for 3 days.
After three days, siphon off the liquid tea by filtering the mixture though a burlap sack. Pour the tea into a hand held sprayer and apply to leaves in the evening.
Remove affected leaves and discard severely affected plants. Use a plastic bag to carry the plant debris out of the garden. Spores can live for years waiting for the right growth conditions, so either burn the waste or discard it in the trash. Don't compost it!
This page contains the following solutions.
A good solution to get rid of this powdery mildew is to make a solution of dry powered milk and spray your plants. This is a tip I learned at a Master Gardener class. It works!
There are many articles posted on the Internet reporting that ordinary cows milk diluted with water to about a 10 % solution and sprayed on plants is highly effective as a preventative and as a treatment for various types of powdery mildew.
It's that time of year again, the garden and the garden pests are back with a vengeance! This is what white mold looks like.
