With Humidity - Comes Powdery Mildew

During the summer months humidity is expected, and along with this type of weather comes one of the most easily recognized types of fungus called "Powdery Mildew".

While no plant is immune to this disease, there are certain plants that are more susceptible than others such as:
- Honeysuckle
- Lilacs
- Monarda (Bee Balm)
- Roses
- Crab apples
- Phlox
- Eggplants
- Cucumbers
- Squash
- Grapes

Powdery Mildew looks just like the name suggests. It tends to look like someone sprinkled powder on the tops of your leaves. The color of the powder can be either white or gray and will either be in blotches or cover the entire leaf and stem of the plant.

The good news is while this mildew will make your plant look unattractive it rarely kills the plant itself, although in some cases on vegetable plants it can hamper the production of vegetables by aborting the flower that would normally produce the vegetable.  Often times, a badly infected leaf will even fall off the plant.

How does it occur?
Often the spores are overwintered in plant debris and start producing in spring. They are then blown on to your plants most often by wind or even insects. The fungus most often gets worse when there is prolonged dampness or humidity, your plants are crowded which causes a lack of air circulation.

How can you control it?
-Remove infected leaves.
-Improve the air circulation by thinning out the plant.
-Do not fertilize until the problem is corrected, as the fungus prefers young growth.
-Water only the base of the plant and not the leaves, and only water in early morning.
-Apply a Copper Soap fungicide.

You can also try an organic homemade method following the recipe below:
Mix together the following ingredients:
1 tablespoon baking soda
1/2 teaspoon liquid dishwashing soap
1 gallon water

Try this mixture on a small area of your plant first and avoid spraying it on your plant in full sun.