Golden zucchini question

Asked June 15, 2018, 6:55 AM EDT

I planted my golden zucchini about 3 weeks ago and they are growing great, but the only problem is that the leaves appear to have what I think is powdery mildew. I make sure not to get the leaves wet when I water them so I’m not sure how this happened. Can you tell me for sure if this is powdery mildew?

Kent County Michigan

1 Response

If you see the white spores on the undersides of the leaves, then this is probably powdery milder. I say that because some zucchini leaves will have a mottled appearance so if you have that kind, then this may be to be expected.

Look closely at the leaves and see if you can see the talcum-like powdery growth (that you may be able to rub off). If so, you can treat with a copper-based fungicide that is good for use on vegetables (following application directions).
You are doing the right thing by do all you can to keep the leaves from being wet but know that growing conditions (warm temperatures and moisture) can be the primary factor for the spread of the fungal spores.Below are two MSU web sites that will provide you with more details about the fungus and what you can do to address the problem which can occur on any vine crops. The info focuses on pumpkins but all would apply to zucchini. Hope that helps!

http://msue.anr.msu.edu/news/watch_for_powdery_mildew_on_vine_crops

http://msue.anr.msu.edu/uploads/files/powdery_mildew.pdf