Hi Maybe someone can help me, We have some Crimson maples in our park, and it looks like they have mold on the leaves, and the leaves are all curly. Would anyone know what that is , and what can be done about it? thankyou. Bert
Hello, The hot, dry summer in the local Vancouver area is causing a lot of stress on maples. The maple is likely suffering from a combination of verticillium wilt and drought stress. Have a look at this thread and this thread.
Yes, more likely powdery mildew. My error. Not quite sure what I was thinking! Powdery mildew on maples from Oregon State University Plant Disease Control Powdery mildew (PDF from City of Toronto)
Additional Ifo Daniel, you were probably thinking about my reply to a SF maple being eaten by vegetarians...haha. Here is a site that may have additional information in regard to this problem: http://216.239.57.104/search?q=cach.../gt1044.pdf+Orthene+and+Japanese+Maples&hl=en It may be Powdery Mildew but I don't see it that much on Maples and here in the south Powdery Mildew is prevalent. Are these Acer platanoides 'Crimson King'?
Hi Bert: Is the mold on top of the leaves or is there a white covering on the underside of the leaves? If the Maple is a Norway Maple the culprit may have been Aphids which leads to a sooty mold on the leaves. The leaves can dry up due to the Fungus as well as from the Aphid damage. The Maple is quite susceptible to verticilium wilt. I lost our Crimson King years ago due to verticillium. Elmore: We seldom see Powdery Mildew here also but we can see it on Grapes if we have a prolonged wet Spring. Daniel: If the trees die it will probably be due to verticillium as a result of prolonged stress. A drought is more of a stresser to the tree than the attack of Aphids and the resulting sooty mold will be. Also, verticillium wilt can indeed cause a faint whitish colored film-like covering over the leaves before the leaves shut down and shrivel up. Jim
