Hi,
I have four peonies--three Magical Mystery Tour and a Cora Stubbs--all planted in 2014. I've always cut them down in the fall, but last year I did not have a chance to do it.
All four are flowering nicely now, but the leaves are covered with white spots -- what are they, and should I do anything about them, and when?

(I've seen an old thread with a similar question, but it was posted in late August, when peonies were getting ready to go into dormancy.)

Thank you very much!

P.S. We've had a lot of rain recently.

powdery mildew?

graycrna4u said: powdery mildew?

Should I do anything about it? I heard that you shouldn't spray against mildew on hot sunny days - we've got a lot of those coming up in Baltimore.
Should I just wait till autumn, cut the peonies down then, and hope they'll do better next spring?
Thank you very much!

Hi Sasha, treatment for powdery mildew is more preventative than corrective. It doesn't really hurt the peony, luckily! I'd remove the worst impacted foliage if it doesn't take too much green off your plant but otherwise I'd just look to prevention for next spring. Make sure to remove all foliage from the garden this fall to hopefully keep it from happening again next year.

Liz and I also use 50/50 milk/water to spray powdery mildew. It treats the fungus and helps stop insects from spreading the disease during the growing season.