Beech Leaf Disease (BLD)
First it was the Chestnut (Chestnut Blight), then the Elms (Dutch Elm Disease), then the Ash trees (Emerald Ash Bore Beetle)... Now the magnificent Beech trees are under attack.
Most impressive American Beech tree, @ Longwood Gardens.
On the East coast we have what's called the American Beech tree. This is a slow growing, native deciduous tree with fine gray bark (you will often notice knife carving “art” on the trunks of these trees). They grow quite large and provide exceptional wildlife value in the form of the Beech Nut (yeah, that one!). Beech trees are not just slow growers, but they are extremely picky about soil conditions, choosing only the most fertile, moist, well drained soil.
American Beech, reaching for the sun @ Ridley Creek
When America was first colonized, farmers quickly realized that areas heavy in Beech trees were also areas with soil perfect for growing crops. The Beech groves were clearcut and farms were developed…
…In Middletown Township however, Beeches are ubiquotous. Maybe we owe it to our hilly terrain that farm’s didn’t appear everywhere, or maybe it’s just one of the primary trees that have chosen this as a home for thousands of years. Regardless, Beeches dominate the landscape in the forests of Tyler Arboretum and Ridley Creek State Park. Beeches provide much of the shade and organic matter that covers Ridley Creek and Chester Creek, creating the riparian buffer that helps keep our drinking water clean.
Example of shrunken leathery leaf before it dies and falls off. Dark stripes between the veins help indicate BLD.
The scourge on the Beech trees was first observed in Ohio in 2012. Trees were dying everywhere, the youngest ones the fastest. The symptoms were simple: rapid defoliation and shrunken leathery leaves. The cause was initially unknown, with agencies researching whether it could have been caused by a fungus / bacteria / virus... It wasn't until small nematodes (tiny worms, less than 1mm in length) in the leaves were observed that we had any idea what was going on. The nematode was native to Japan (Litylenchus crenatae). It's believed that the Japanese Beech tree had adapted with this nematode over time and is not affected severely by it, but our American Beech trees have not yet had the same opportunity.
Extreme defoliation, especially in young Beeches @ Ridley Creek
Recently, Beech Leaf Disease has spread to Middletown Township. The effects are especially obvious in Ridley Creek Park, along the paved trail near the creek. Areas of formerly dense shade are now mostly defoliated. Young trees are expected to die within 2-5 years, mature trees may take a few more years to die after that. Mortality is expected to be around 90%.
Try not to get discouraged! While Beech trees are an important part of our ecosystem, we aren't exactly losing natural lands. Some Beech trees will survive, and create new disease resistant cultivars that will continue into the future. In the meanwhile, new trees will establish themselves in surprise sunbeams.
The good news is that states and universities everywhere (Penn State too! as you can see in the link below) are aggressively researching this disease and treatments. To learn everything you’d ever want to know about the disease itself, check out information from Penn State here:
Penn State Extension - Beech Leaf Disease
For treatment, the most promising technique is actually as simple as fertilizing twice a year with high potassium fertilizers. This may not be feasible for large tracts of forest, but if you have only a few Beech trees under your stewardship, read more about the most effective treatment here: