From staff reports
Some ash trees throughout the region are losing their leaves, and homeowners are wondering why.
It's the anthracnose leaf spot infection, it's nearly impossible to stop, and it won't kill the tree, said Doug Courneya, regional University of Minnesota Extension horticulture educator.
The disease, which can also affect maple, oak and walnut trees, usually affects only the leaves closest to the trunk and not the ones farther out that are more important to the tree, he said. Homeowners complain about having to rake in spring, but he said the leaves can be safely mowed and mulched, he said.
Some fungicides will kill the disease but the chemical has to be sprayed on at just the right time and over the entire tree, which is impractical or impossible for most homeowners, he said. It's well past the time to spray for this year, he said.