It’s been a bad year for maple trees. Norway and silver maples across the Northeast and Midwest are ravaged this year by tar spot (the Rhytisma acerinum fungus) and (maybe less widespread) anthracnose, as I posted on GWI last week.
In Western New York, the Norways look the worst; their shriveled leaves have been falling since August. The silver maples (shown at top) aren’t quite as bad. If I needed another reason to dislike these trees, this blight provides it. Apparently, the soaking we got in May gave the fungus what it needed; it is visible almost every year, but usually not so much that we don’t get some decent color.
Treatments other than conscientious leaf removal (which I always do anyway) are not advised by the various extension sources I’ve consulted, and I’m glad there are no plans by the city to carpet bomb the streets with fungicide. I did hear of one possible remedy—though I’m doubtful. A Facebook friend contacted me after my GWI post, and said she noticed the problem in midsummer and her arborist did this: “provided in-ground injections of concentrated fertilizer. Within one week, the tree markedly improved, and has been fine since that time.”
I’ve never fertilized any of my trees, other than the usual additions of mulch and compost to the garden beds that surround them, and I’d never heard that injecting fertilizer would help with disease. Well, I’m only vaguely aware of the practice of injecting fertilizer—I’ve certainly never done it. Interesting!