Often by mid-August ( I realize it’s not “mid” yet, but, close enough), summer’s heat and dry is stressing my American Sycamore, Platanus occidentalis.
It’s a tough tree and hard to kill, but it likes a river bottom situation with plenty of regular moisture. In droughty times, the Sycamore will shed leaves as a survival mechanism, though mine has never gone completely nude. But Sycamores are also subject to some disease problems which can hamper growth and beauty.
The upper canopy of my Sycamore looks healthy to me–green and lush–though that might simply be a result of distance, rather than reality.
Two lower branches (which I plan to remove soon; then again, I’ve been saying that for a while) demonstrate foliage damaged by one of Sycamores’ various banes–anthracnose.
According to the Missouri Botanical Garden website, Anthracnose is caused by a fungus, Apiognomonia veneta, and is common in urban Sycamore trees. The brown spots show a tell-tale “V” shape and the fungus can eventually cause the whole leaf to brown and drop prematurely.
The article also mentions tiny black spots which are the “fruiting bodies” of the fungal spores and, sure enough, they’re visible on the undersides of some of the leaves.
My Sycamore shows some anthracnose damage almost every summer, but it’s usually worse in wet years, which 2016 certainly qualifies for. Spring saw deep, soaking rains and that set up a situation for fungi to flourish. Additionally, there have been some heavy rains this summer, no doubt continuing the stage for fungal spread.
What to do? Well, I probably won’t do anything. I’m certainly not going to spray with a fungicide, but as good garden sanitation practice, I should rake up the fallen leaves.
There aren’t many leaves dropped this summer,
… just enough that one or two hitch a ride on the the dog’s fluffy tail or for some to whoosh into the house when the back door is opened. My Sycamore stands in a work/storage area, and I tend to procrastinate in regular tidying of this area. Plus, as a wildlife gardener, I’m prone to leave limbs and leaves on the ground as cover for a variety of critters. I suppose a little compromise is in order: picking up potentially diseased foliage to protect the tree’s viability, while avoiding the sterility brought on by obsessive weeding, raking, and “cleaning” of garden areas.
During prolonged drought periods, I soak the soil around the tree once or twice a month, which prevents massive leaf drop, but with this year’s summer rains, that hasn’t been necessary.
I’ll keep a watch on the tree as August progresses into September, but unless I see significantly more damage, I won’t fret about this tree.
There seem to be plenty of other things to fret about!
Thanking Pat of The Squirrelbasket for graciously hosting this fun and interesting meme about trees. Check out her blog to learn about trees from all over the world.