Powdery Mildew on Pumpkins, Cucumbers and Squash

We returned home from a lovely long weekend at a friend’s cottage to discover this…

Powdery mildew attack!

Powdery mildew attack!

… our lovely pumpkin “octopus” – the sprawl of pumpkin leaves which has been creeping across the lawn, had been almost entirely consumed by powdery mildew, in a span of only 3 days! This nasty, fast-spreading fungus is characterized by fuzzy white patches on the leaves of your pumpkin, zucchini, cucumber and squash plants. (Although it can affect other plants too!) Your plants are at particular risk during periods of high humidity and damp weather. The spores growing on the leaves eventually block out the leaves’ ability to photosynthesize, wreaking havoc on the plants’ productivity. In other words, it’s bad news!

How to get rid of this stuff?! For starters, I immediately removed all of the infected leaves (my heart breaking a little with each snip of the scissors.) I put all of the cut leaves in the green bin, NOT in the compost, since I don’t want it to spread any further than it already has.

Pile of mildewed leaves next to ravaged pumpkin plants. Sniff, sniff...

Pile of mildewed leaves next to ravaged pumpkin plants. Sniff, sniff…

Next I did a thorough internet search and it seems that there are two possible organic “kitchen remedies”. The first is a mixture of baking soda, soap and water. I tried this last year when our squash were infected with a less severe but equally annoying bout of mildew. It didn’t seem to work well.

This time I am going to try a milk solution on the leaves of the pumpkins and zucchini, as well as the cucumbers because there are definitely a few leaves with early signs of mildew. (Prevention is the best medicine.) Growveg.com suggests that a mixture of 3 parts milk to 7 parts water is a good ratio to try. Wish me luck! I’ll let you know how it goes…

Early signs of powdery mildew on cucumber leaves.

Early signs of powdery mildew on cucumber leaves.


  1. Man, I wish I had seen this post earlier… I would have suggested some breast milk for that solution. Seriously, I’ve heard it does wonders so why not on plants?

  2. So how did it go? I live in New Orleans and weve had torrential rains this summer? How did the milk help?


    • Sprouted says:

      Hi Stephen, Sorry for the delayed reply! The mildew won that year, I’m afraid. This year we are growing our squash and pumpkins vertically, to try to keep things as dry as possible. So far, so good!

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