Hello Charmer friends……it is hot, hot, hot and humid the last few weeks. As I walked my garden early this morning, before the bustle of the world invaded my ears, and the heat threw me inside, I gazed over my garden children to see how everyone’s looking and feeling.
As I walked through her I notice Powdery mildew, a good topic for master gardening series.
“That beautiful season the Summer!
Filled was the air with a dreamy and magical light;
And the landscape
Lay as if new created in all the freshness of childhood.”
– Henry Wadsworth Longfellow
One of my most favorite cottage garden perennials is Phlox which features charming, vibrantly colored flowers that add pops of red, pink, blue or purple to your spring or summer landscape.
Numerous varieties exist, there’s an annual phlox (Phlox drummondii) which is a fragrant Texas native. Garden phlox (Phlox paniculata) is a perennial favorite that winters well in plant hardiness zones 4 through 8. To check you zone click here.
Although considered hardy little plants, phlox can suffer from the occasional plant disease. One in particular is Powdery Mildew which is the most common to affect Phlox.
Several mildew diseases sometimes affect different phlox varieties, but powdery mildew is the most common issue, particularly in areas that experience hot, humid summer weather. Just like the name implies, powdery mildew symptoms include a white, powdery substance appearing on the tops of leaves.
This is a classic example of how powdery mildew looks on a leaf.. White speckles of white powdery on the leaves. This isn’t a phlox but a Serviceberry shrub in my front yard. Powdery mildew affects many plants.
A severe case of powdery mildew which will cause the plant to drop from the plant. Powdery mildew is a fungal disease that is a common summer problem for plants and loves hot and humid conditions which we cannot control. It thrives in temperatures between 60 and 80°
Disease Life Cycle:
Spores overwinter on diseased plant parts, and begin asexual production of new spores once the weather warms. New spores are carried on the wind to other parts of the plant, or to other nearby plants. Spores never stop producing more spores, so if infected leaves are not destroyed, the problem will only get worse.
- To keep powdery mildew at bay maintain good air circulation around your plants. Make sure they’re neither crowded nor shaded when you plant them.
- Also important to avoid using the sprinklers in the evening, so the water doesn’t stand on the leaves too long. The water itself doesn’t cause more mildew, but it allows it to be transported to the other leaves on the plant easier.Natural Treatments:
- Mix a 10% solution of milk to water, and spray once a week on the plants that have it.
- Baking soda – the same stuff you use for making biscuits or deodorizing the refrigerator – is highly effective against powdery mildew. To mix your own solution, for each gallon of water in your sprayer, add 1 Tablespoon baking soda and 2.5 Tablespoons of horticultural oil. It must be sprayed every week to protect new growth on the plant.
- Garlic is another kitchen remedy is garlic extracts, which can be made by blending two bulbs (not cloves!) of fresh garlic in a quart of water with a few drops of liquid soap. The liquid should be strained through cheesecloth to remove solids and then refrigerated. That concentrate should be diluted 1:10 with water before spraying.
- Oils, vegetable seed oils such as canola oil can be used, at a rate of 2.5 to 3 Tablespoons per gallon of water, with the addition of a quarter-teaspoon of liquid soap to emulsify the oil. Most commercial horticultural oils already have an emulsifier added, so additional soap is not needed. Neem oil is labeled for control of powdery mildew, rust, blackspot, botrytis, downy mildew and other diseases. Spraying with 2.5 Tablespoons per gallon of water every 7 to 14 days is recommended.
If you don’t want to mess with making your own, buy 70% Neem Oil which both treats existing powdery mildew and protects the plant against further infection.
Interestingly enough, the most effective measure in preventing and treating powdery mildew is to spray the foliage of your plants daily with plain water from the hose. Powdery mildew hates water! The only caveat with this method is to be sure you do it early in the day so that the foliage completely dries before cooler evening temperatures arrive, otherwise you may invite other fungal diseases, such as black spot, into your garden.
Enjoy your day…walk around your garden or someone else’s’, no matter how small or large, and glazed upon the beautiful flowers…and absorb their energy inside.