Some of you may be aware of my (perhaps excessive) love for physocarpus in all its varieties and seasons. May is perhaps the glory season for this plant,
so you can probably imagine my distress when yesterday found one of the six-foot Coppertinas in the front yard at the old house literally covered in powdery mildew. This is what the spring foliage on Coppertina normally looks like:
powdery mildew covers all those leaves with a thick white powder and eventually turns them into blackened twists. PM is not uncommon on physocarpus, but, in our yard at least, it had attacked only the occasional stem and posed no real problem. Yesterday, I could find only a single healthy stem on one Coppertina and about a third of the plant on the other.
Because there is no real cure for this plague and it can spread, the only hope was radical surgery: every speck of mildew had to be removed to keep it from spreading to the other plants, which as of yesterday afternoon were mildew-free. I didn't have a camera with me, but the larger Coppertina has now been cut down to the ground, leaving quite a large gap in the front hedge at Chipmunk Ridge.
We can only hope the patient survives.