If your Maple leaves are covered in spots, you’re not alone.
Gary Henderson, Garden Town manager at Jacobsen’s Flowers and Garden Town in Lake Orion, said he has been fielding questions from concerned residents about their Maple trees for the past week.
‘When I see them get out of their car carrying a branch or a bag of leaves, I know what they are going to ask,? he said.
Henderson said area Maple trees are showing signs of a leaf fungus called Tar Spot Disease much earlier this year then normal due to the cool weather and moisture we’ve had this summer.
‘The infection occurs back in June, it’s a fungal disease,? he explained. ‘At first, you will get these little yellow spots all over the leaves…then they get bigger, and when they turn black, that’s actually when the fungus gets fruit on it.?
Henderson said when the spots begin to turn black is usually the first time people notice it.
‘There are black spots earlier this year because of the weather we’ve had,? he said. ‘It brought it on faster…a lot depends on the environment, but the spores are always there.?
If you have already been hard at work raking up leaves in your hard, Henderson said you are not alone.
‘When the leaves change colors, they change colors with the spots on them,? Henderson said. ‘And they will fall off earlier. There are lots of them off the trees already.?
Although the fungus will not kill the tree, Henderson said there isn’t much to be done at this stage other than make sure infected leaves are carefully cleared away.
‘It occurs late enough in the leaves where now the fungus has already done its job,? he said. ‘Michigan State University recommends cleaning up the fallen leaves, bagging them and removing them from your yard. Don’t compost them or use them for mulch.?
To help prevent the fungus next year, Henderson recommends spraying trees with a fungicide in early spring when the leaves first come out.
‘Then spray them again every 10 to 14 days, through June,? he said. ‘Daconil is a common fungicide…but there aren’t any guarantees with that.?
Cleaning up the infected leaves can help reduce the problem next season. The fungus will remain on the leaves around the tree until weather conditions are right next spring.
The spores then float through the air, attaching themselves to the Maple buds and small leaves, repeating the cycle.
‘It’s a nuisance, a cosmetic nuisance,? Henderson said. ‘But at this stage, there’s nothing they can do. Just relax and clean up the leaves, and know it won’t kill your tree.?