Connecticut Trees Hit Hard By Beech Leaf Disease In All 8 Counties

CONNECTICUT — State scientists are reporting a huge surge in beech leaf disease sweeping through Connecticut forests and backyards.

First detected in lower Fairfield County in 2019, BLD is now widespread on American beech (Fagus grandifolia) throughout all eight Connecticut counties, with symptoms most severe in Fairfield, New Haven, Middlesex and New London Counties.

Botanists from the Connecticut Agricultural Experiment Station are reporting that BLD has increased dramatically in both severity and distribution in 2022 compared to 2021.

Science magazine explained that the rapidly-growing threat critically threatens Northeastern forests, where beech is one of the main tree species. The disease has now been found in eight states and in Canada.

Beech leaf disease is caused by a foliar nematode currently known to cause disease on only American, European, and Oriental beech. Symptoms observed in foliage this year are the result of nematode migration in autumn from infected foliage into nearby buds, where the nematodes spend the winter and reproduce.

The symptoms on beech foliage, best observed from below looking up into the canopy, are characterized by dark striping between leaf veins. Advanced symptoms observed this year include: aborted buds (i.e., no leaves emerge); distorted leaf enlargement; cupping, browning, and yellowing of foliage; branch and tip dieback; and in some cases, premature leaf drop.

Scientists at CAES have joined forces with researchers in Ohio, Pennsylvania, New York, Canada, and the United States federal government to study disease development, transmission, and control. Research on control options, conducted in Ohio, has shown some promise of recovery after five years of treatments of a phosphonate-based product, according to a news release from CAES.