This year, I discovered that a simple solution of baking soda in water is effective enough to mitigate powdery mildew growth on zucchini, butternut squash and pie pumpkin leaves. 1 Tbsp in 1 Gal of water, applied twice a week with my little hand-pump sprayer, seems to be doing the trick without any adverse effect on the plants so far.
This year, I discovered that a simple solution of baking soda in water is effective enough to mitigate powdery mildew growth on zucchini, butternut squash and pie pumpkin leaves. 1 Tbsp in 1 Gal of water, applied twice a week with my little hand-pump sprayer, seems to be doing the trick without any adverse effect on the plants so far.