They were here 40 years ago when I moved in. Only when the stately, smooth gray barked giants on my wooded lot annually dropped their beech nuts, protected in their soft but spiny shells, did I really notice them. Popping open for easy access to the wildlife that cleaned them up in no time. It’s a beautiful tree.

But now my beech trees are not well at all; the saplings surrounding the parent trees have died. Sadly, they are infected with beech leaf disease.

In the swelling leaf buds, nasty microscopic roundworms called nematodes are making havoc with the growing tissue, spreading a fungal disease that disfigures the leaves with darkened leatherlike banding between the veins.

Premature leaf-drop and branch die-back results. The sun blazes through the canopy now. Likely, all my beech trees are dying.

Lake County in Northeast Ohio was the first to observe trees with this serious threat in 2012. Since then, it has spread rapidly to at least a dozen more states in the central and northeast U.S. and into Canada. The disease has no preference between species of beech, affecting the American beech as well as the European beech cultivars.

It is assumed the nematode is not native to North America. It is unusual in that it is found in the foliage and not the roots of the tree. Researchers think the nematode travels from leaf to leaf by water droplets and have found that the nematode survives the digestive tract of caterpillars / moths as well as on the plumage of birds, thus the ability to spread the vector.

Why now and not before? Researchers just do not know.

They do know the prediction for survival of the beech is not good if defoliation is more than 40%. Young trees are most susceptible to succumbing to the disease.

A recent study by a team of scientists at the Yale School of the Environment found the leathery sections of a leaf at a cellular level were 249% thicker than a healthy part of the leaf. Deformed leaf pores (stomata) reduce the ability for exchange of gases and reduced photosynthesis capability. They conclude that the reduced ability to store carbon potentially leads to the tree dying.

A beech could have a 300- to 400-year life with its tall canopy an essential home to birds and mammals. Their high-fat nut is an important food source. There is no cure yet. Trials are underway to find a treatment. This may help the beech varieties we plant in landscape settings. But our precious forest canopies are poised to lose yet another important species at an alarming rate.

Many current university Extension bulletins abound with warnings in areas the disease is spreading into, including a recent update from OSU Extension with maps at https://go.osu.edu/beechleafupdate.

Karsnak is an Ohio State University Extension Master Gardener Volunteer in Mahoning County.