Oaks and sycamores losing leaves 6.18

Posted in 2008 June

A cool, moist spring has led to an increase in sycamore anthracnose and oak anthracnose, diseases affecting the foliage of sycamore and white oak trees, according to the Ohio Department of Natural Resources (ODNR).

“The diseases appear to some extent each spring, but symptoms are unusually severe this year,” said Dan Balser, forest health administrator of the ODNR Division of Forestry. “Diseased trees will be stressed, but should survive with little permanent damage.”

These leaf and twig diseases are caused by a family of closely related fungi and are responsible for the widespread defoliation observed on sycamore and white oak trees in recent weeks. These diseases prevail as the leaves begin to emerge from the bud and expand.

By early summer, re-growth will be underway. New shoots will arise from buds that would have remained dormant. Summer heat and dryness will prevent the new shoots from being attacked by the fungi and the trees will once again leaf out.

However, property owners should be aware that weakened trees may be subject to branch dieback and insect attack. Disease resistant varieties of sycamores and white oaks may be obtained from local nurseries for home and landscape plantings.

Other hardwood trees such as ash and maple are also subject to anthracnose diseases. However, sycamore and white oak appear those most affected this spring.

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