Milk Spray for Powdery Mildew

At our Uganda clients, powdery mildew is the main disease pressure. In another region of Uganda the current treatment is a milk spray, consisting of water and whole milk every two weeks. One of our client tried it, and doggone it, it worked; they reported a dramatic reduction.

Is anyone else using milk spray for powdery mildew? The ratio is 70/30 water to milk. They use whole milk as that’s all they have, but I heard skim milk works as well.


I recently came across this story about milk/whey being used for PM in vineyards (though it’s from 2002):

There’s research to support it. For those who like scientific literature:

And another:

I’m using milk and water mixed about 1:4 on my powdery mildew-stricken lilacs, and while the results haven’t been magnificent, it does seem to help. (It would probably help more if I remembered to spray them on a regular basis, but alas…) I may try it on cucurbits this season, too.

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I’ve done it on lilacs.

By midsummer most years my lilacs are pretty powdery and a dilute milk spray has helped in the past.

Just don’t forget to water it down by at least half…



Interesting. I have an Indian Free peach tree that seems very susceptible to powdery mildew. I will have to give this a try.

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I’ve tried it on roses and it didn’t work.

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Bumping this thread to see if any confirmation of success was had. I am wondering as we occasionally have a bit of milk which spoils before it’s used and it would be great to not dump it down the drain if this is an effective (up cycling in my case) method.

I have tried it on pumpkin and zucchini, it worked for me. I was pretty surprised when it worked as I didn’t use any special ratios, just a little water in an old milk bottle and splashed it on. .

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