About two weeks ago, a friend arrived at dinner with some twigs and leaves of her japanese maple in a plastic bag. She wanted me to take a look outside, in daylight, where I could clearly see that the ends of the leaves were brown and tattered–just like the leaves in the above photo.
“Do you know what’s wrong? Who should I call?”
“Oh, nobody,” I replied, handing the bag back. “Mine does this every year. This is what they do. It’s sunburn or wind burn. They’re very prone to that.”
She was totally unconvinced, I could tell, by the look on her face, telling me that hers had never done this before. But she’d just put in a new system for treating the water in her pool–and we’d just come through tropical storm Irene with winds that blew for several hours in the gale force range, if not higher. She had lost power for a couple of days; I had not. And it was just shortly thereafter that we both noticed our trees looking like someone had burned the tips of their leaves. I suspect that “someone” was Irene.
I hope she will be reassured when I give her this article from my print copy of Organic Gardening. It primarily talks about the beauty of japanese maples but does get a bit into the problems and diseases, verticilium wilt being the primary disease. But it says that by far the most vexing problems on the laceleaf and threadleaf types, which we both have, are the sun scald and wind burn, which you see above.
And how do you know whether you have sun scald, or wind burn or something more serious? Generally if you have the cultural problems like sunscald or wind burn , only the leaf margins are affected. The leaves look a little ratty around the edges but the center of the leaf stays pretty much unaffected.
If, on the other hand you have a more serious problem, the whole leaf will be affected right down to the center of the leaf. That’s when you should take a portion of the plant to your cooperative extension agent or call an arborist.
So I hope that clears things up for folks–and I hope anyone with some storm damaged trees just has cosmetic damage and nothing more serious. Hurricanes can be notorious for blowing disease and pathogens hundreds of miles along with them. Let’s hope Irene wasn’t one of those hurricanes!