Beech Leaf Disease Coalition

A group of environmental organizations finding ways to address BLD-related forest degradation

Local land managers and environmental organizations are actively working to manage forests affected by BLD. The newly formed BLD Coalition, a group focused on Westchester and Putnam counties with representatives from Westchester Land Trust, Teatown Lake Reservation, Westchester County Parks, Hudson Highlands Land Trust, Mianus River Gorge, and North Salem Open Land Foundation, are setting forth recommendations for managing stands affected by BLD with the primary goal of promoting the establishment of young native forest.

What is Beech Leaf Disease (BLD)?

Beech leaf disease is a new disease in NY. It affects both native and ornamental beech, causing rapid dieback of the tree canopy. Beech can be identified by their distinctive, smooth, gray bark.

Close up of football shaped buds against the backdrop of a smooth gray-barked small tree. — A small beech tree with classic smooth, gray bark and emerging buds. Photo by M. Jones, NatureServe, is licensed under CC BY 2.0.

What are its impacts?

BLD significantly stresses beech trees reducing their overall health and life span. Increased light from leaf dieback will promote new plant growth, especially of unwanted species like aggressive vines and invasive brush. The loss of beech nuts reduces food for local wildlife, and the loss of beech will reduce carbon storage to combat climate change.

What does BLD look like?

BLD is very easy to identify because it causes a dark banding of beech leaves in the early stages. In later stages, leaves curl and drop during the growing season.

Early stage Beech Leaf Disease (BLD) on American Beech

Photo Credit: A. Middlebrook, North Salem Open Space Conservancy

Photo Credit: D. Begley-Miller, Teatown Lake Reservation

What causes BLD?

The disease is associated with a leaf nematode, which is a microscopic worm. It is unclear if the disease is directly caused by the nematode or its association with another pathogen.

How is BLD spread?

BLD spreads rapidly to unaffected beech, but the way it spreads is still unknown. In 5 years, it has spread to 36 counties across New York State. Locally, it spreads to all beech on a single property within two to three years.

Do trees infected with BLD die?

BLD was first detected in the United States in Ohio, where in 7 years, 10-15% of trees with BLD died. Spread and decline of beech in Westchester is much more rapid than in Ohio, but it is unclear what mortality rates will be in this area.

Can trees with BLD be treated?

There is currently no approved treatment for BLD. Experimental treatments for newly infected trees are available, but their effectiveness is not known. Contact your local certified arborist if you’re interested in experimental treatment options.

What is being done regionally to address BLD?

Local land managers and environmental organizations are actively working to manage forests affected by BLD.

Current actions include:

Education – public outreach and education about BLD are necessary for identifying areas of spread and providing support to affected sites.

Mapping local stands – land managers are working to identify areas of their property with many beech trees to determine areas that will most be affected by BLD.

Mitigation – natural resource professionals are using existing knowledge from past disease outbreaks to implement strategies that will promote reforestation after BLD infestation.

Local research – area organizations and universities are conducting research into the best strategies for managing future sites affected by BLD.

Monitoring spread and mortality – the NYSDEC is working diligently to map the spread of BLD statewide and determine mortality rates. Individuals can report sightings of BLD here. Alternatively, individuals can report sightings using iNaturalist.

How can I help?

Consider actively managing your forest stands by encouraging new tree seedlings to grow. Tips on what to plant and how to protect them are available.

Volunteer with a local conservation organization to help them manage their forest stands.

Planting Tips Volunteer