Powdery Mildew
Controlling and Preventing Powdery Mildew on Plants
Saturday May 31, 2008
Summer is heating up and with heat comes humidity. If you think you can’t stand high humidity, think of how your plants feel. They can’t grab a lemonade and sit in the shade. But not everything in the garden hates high humidity. Powdery mildew likes it just fine, thank you. Powdery mildew is an odd little fungus that can’t handle truly wet conditions, but will spread rapidly in humid conditions or the dampness of the shade.
There are many, many kinds of powdery mildew, but they all look like a dusting of talc. The picture to the left is of a mildew resistant phlox ‘David’. While growing resistant varieties is the first step in controlling powdery mildew, it is by no means the end all. Here are some more tips in the endless battle against powdery mildew.
Photo: © Marie Iannotti (2008) licensed to About.com, Inc.
Comments
Your article on mildew offered some more tips. But there is no link to such offer. Very poor.
Hi Elizabeth,
The link is the title. I’ll add an additional link at the end of the blog, so it’s not so confusing.
Terrific article on powdery mildew. I’ll put the info to practical use right away…
I use Neem Oil (diluted as directed) successfully for black spot/powdery mildew on my Viburnum and Rose bushes. Smells yukky, but works well!
From personal research, I have read that a store-bought milk solution (anywhere from 5% milk and 95% water, to 50% milk and 50% water) sprayed on the foliage of plants combats not only powdery mildew, but also other fungus-related problems. The principle is based off of the fact that milk contains beneficial salts and potassium, which are absorbed by the leaves and boost the plant’s immune system. With a stronger immune system, the plant is able to fight off fungi and diseases.
I spray a 10% milk solution on my plants every week, during the evening. The following morning, I rinse of the leaves with hose water. I do not recommend the use of whole milk, since it may clog some sprays. Low fat or fat-free milk are preferable.
It is quite hot and humid down here in Florida, but I have yet to bump into problems with fungi. Maybe it’s the milk, or maybe I’m just lucky!
There is also the possibility that milk works not only as a fungicide, but also as an organic foliage fertilizer.
There are plenty of articles out there about this subject, but here is a good one to start off with: http://www.thefrugallife.com/mildew.html
SERINADE…. organic works on everything
Jeff, you got me curious. I had never heard of Serenade and I went poking around for info on it. It does claim to work on everything from powdery mildew to grape bunch rot. I’ll definitely give this a try. Thanks.
Nathan, That was the Tip of the Week in the newsletter 2 weeks ago. I’m glad you wrote in to say it works. If it works in Florida, it must be OK.
Previous garden tip: Got milk? When you rinse out your milk cartons, use the water on your plants. A dilution of milk seems to improve the disease resistance of plants. The potassium phosphate in the milk revs the plant’s immune system. And scientists have been conducting studies on milk’s fungicide properties. It seems a week solution, 1 part milk to 5 to 10 parts water, sprayed on plant leaves every 7 - 10 days helps prevent powdery mildew and may help control other fungus problems, like black spot and rust. Don’t use undiluted milk or you’ll wind up causing problems, like sooty mold. And don’t worry, it won’t smell sour.