Maple tree disease is temporary

Q. Why are the leaves on my maple turning black on the edges and dropping from the tree?

Mike from Columbiana and Ron from North Jackson

A. We have not seen this many questions on the same topic since the invasion of the stink bugs. And most of you have not seen this many leaves fall off trees since last autumn.

The brown and blackened edges of maple leaves this spring are caused by maple anthracnose. Anthracnose diseases are rather common on shade trees. But there are many different anthracnose diseases, each affecting a different species of tree. Some cause minimal problems, others cause significant damage. Anthracnose on maple is seen as a minimal problem, causing only an unsightly tree for a few weeks.

Anthracnose rears its ugly head every few years when spring conditions are the perfect combination of “cool and wet” like they were this year.

Our experts say the infection does not generally affect stem tissue on maple trees. Thus, your tree will be all right — just a little unattractive until new leaves grow out.

There are fungicides used for some cases of anthracnose. But the spray should have been applied when the infection started. That timing was a few weeks back in April before the buds even opened. Thus, fungicides will not do anything at this point, so don’t waste your money.

Do not plan to have your maple cut down this spring. Simply rake up the leaves and dispose of them. Avoid putting them into the compost pile. New leaves will emerge on your maple later this summer.

To read about anthracnose of maple and the impact of other anthracnose fungi on different types of shade trees, go to: http://go.osu.edu/blackleaves.

Eric Barrett is OSU Ext. educator for agriculture and natural resources in Mahoning County. Call the office hot line at 330-533-5538 from 9 a.m. to noon Mondays and Thursdays to submit your questions.