‘Tis farewell to the summer squash, with leaves as white as arctic frost –
It was time to put that plant out of its misery, and to cleanse the garden of its disease – powdery mildew. When it first appeared I could have tried saving the plant by cutting off any infected leaves and spraying the good leaves with a fungicide, but it wasn’t worth the hassle. So the plant is gone. Not put into the compost bin (which I don’t actually have right now anyways) but into a plastic bag and into the garbage can. You want to get rid of the fungal spores entirely.
It must have been a good year for it. I have a peony in the front of the house that usually blooms profusely and without any problems, but this year it, too, was covered in powdery mildew and barely bloomed at all. I guess temperature, humidity and spores in the air all came together at the right time, or the wrong time, depending on your perspective. Perhaps one of the biggest factors is the shade the garden gets for so much of the day.
Next year I am going to have to start a preventative program before it becomes a problem. In my research I find that a diluted milk spray helps to control the fungus, in some research even as well as commercial fungicides. I have seen everything mentioned from a 10% milk dilution to a 60% dilution. I think I would be inclined to try the lower dilution first. You have to spray every 7 to 10 days, and after rain, but if powdery mildew continues to be a problem it will be worth it.