Powdery Mildew on African Violets

What is powdery mildew?

Powdery mildew is a gray/white dust on the flower surface and/or leaves. It generally forms in patches and when infected parts are moved, spores are released in a small cloud.  Erysiphe cichoracearum is the specific fungus that causes powdery mildew on African violets and plants can die when the problem goes unchecked! As you can see from the pictures, it is relatively easy to spot it on darker flowers. This one particular Optimara African Violet plant seemed to be the only plant ever affected with powdery mildew in my possession.

Why does this happen?!

Powdery mildew can easily develop without plenty of air circulation between plants, also nighttime temperature fluctuations of more than 10 degrees can also encourage development.

How can you avoid getting powdery mildew?

A good way to prevent this issue is to place a fan near the African Violets. This can help to both improve air circulation and keep humidity down around the African Violets. This is especially helpful with warmer weather on the way.

How can you get rid of powdery mildew?

There are a few ways to get rid of powdery mildew.:

1. Misting the air immediately around affected plants with a household antibacterial spray, such as Lysol is another way to get rid of it.
2. Spray the affected plant with neem oil.
3. Create a mixture of 1 teaspoon of baking soda in 1 quart of water. This is effective on mild to moderate powdery mildew.
4. Use 1/4 tablespoon of Physan 20 concentrate in 1 gallon of water and dip the plant and pots in.
5. You can also spray the plant with the Physan 20 and water solution, but complete coverage of all surfaces is important without, of course, soaking the crown. You will need to spray every 10 days until  the issue is controlled.

Don’t spray with straight Physan 20 as that will kill your plant! Powdery mildew isn’t anything to panic over as long as you get it in check. You can buy the Physan 20 from Amazon right here.