I've recently noticed a number of Diabolo Ninebarks with a strange, fungal-like growth on them. Seems to hit mostly the new growth, but doesn't appear to be powdery mildew. I've not seen it on any other woody plant, in fact haven't seen it before! It is almost hard in texture and causes the new leaf clusters to become somewhat twisted and misshapen. Any idea what this could be?
Hi there. I live in Winnipeg, MB and I have noticed the same white powdery, yet hardish, spots on my ninebarks as well. Other than the infected leaves, the rest of the bushes look fine. I have some that are 3-4 years old and others 2 yrs and less and this is the first time I have seen this. However, we have had a very wet spring and summer so far and the humidity is higher than normal. I am going to assume that this is the reason for it. One that I have at the front of the house gets morning sun, but is then shaded for the rest of the day. It is also in a more "closed in" area of the yard so probably doesn't get as much air flow as the others. The others are in the back and receive full afternoon sun. There are a few spots on them, but for the most part they are fine. I'm not going to go into a pruning frenzy to get rid of it all. So far I've pruned twice this year just to keep them at a decent size. Boy they grow fast!
