Powdery Mildew on Leaves?

Hi Melissa, I did some research and found a few answers...

I got all my information from this website. But I summarized the big points below. For more information you can read the whole thing.

Powdery mildews do not require moist conditions and actually do well under warm conditions. And pumpkins are more susceptible to this mildew than other plants. Which may be why the rest of your plants are doing fine.

Leaves infected with powdery mildew may gradually turn completely yellow, die and fall off. Which it looks like some of your leaves have already done. Severely infected plants may have reduced yields, shortened production times, and fruit has little flavor.

Because pumpkins are very susceptible, it will probably require fungicide treatment. Also, it was suggested to provide good air circulation and avoid using excess fertilizer. Spraying your plants/leaves may help reduce the powdery mildew - but will not control it.

You should use an eradicant fungicide. Oils work best as eradicants and also have some protectant activity. Some examples are Saf-T Side Spray Oil Sunspray Ultra Fine Spray Oil, or one of the plant based oils such as Neem oil or Jojoba oil (a.g. E-rase).

So, oils work best and you might want to look for those at Home Depot. He gives other alternative fungicides besides oil, but he generally says oils work the best.

Good luck, and let me know how it goes :)