Powdery mildew--how much to cut back?
Hi all. This is the first year all my peonies have bloomed. Unfortunately, two of my herbaceous peonies have pretty bad powdery mildew with the humidity we've had here in Brooklyn.
I started using a fungicide but I understand this won't help existing damage. The mildew is on all the plant stems as well as over half the leaves. Should I just cut these plants back to the ground and keep applying the fungicide? I hate to cut them but I don't want to lose them!
Thanks to all for your help.