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Beech Leaf Disease: Causes, Symptoms, and Treatment Options

Beech leaf disease (BLD) is a fatal disease targeting beech trees throughout the northeast; recently, it has been running rampant in New Jersey. The problem is especially bad in Morristown and the broader Morris County area. If you have beech trees on your property or live near a forest, you need to be aware of the signs of BLD so you can act quickly to help protect our native trees.

In this article, we examine beech leaf disease in New Jersey in depth. We’ll look at the causes of the disease, the typical symptoms, and what you should do if you notice any signs of BLD.

Key Takeaways

  • Beech leaf disease was first discovered in 2012, and we are still developing an understanding of its causes.
  • While there is no cure for beech leaf disease as of June 2024, there are several promising leads that require further testing.
  • Microscopic nematodes cause beech leaf disease by draining nutrients from leaves.
  • The most apparent sign of beech leaf disease is the dark banding that appears on infected leaves. As the disease progresses, the leaves will appear crinkled, copper, deformed, shriveled, and leathery.
  • Do what you can to reduce stress on your beech trees to help prevent BLD. If you notice signs of the disease, reports suggest that phosphite fertilizers and Thiabendazole show promise in limiting tree damage.

The leaves of a beech tree demonstrating the dark banding that is a common symptom of beach leaf disease.


Beech Leaf Disease in New Jersey: An Overview

When did beech leaf disease appear in New Jersey?

Arborists first detected BLD in Ohio in 2012, and the disease has quickly spread across much of the northeastern part of the country. In New Jersey, we first detected the disease in 2020 in Essex and Bergen counties. One year later, much of New Jersey reported the disease, including Morris County, Union County, and Somerset County. To date, we have confirmed cases of BLD in the following counties:

  • Sussex
  • Passaic
  • Bergen
  • Morris
  • Essex
  • Union
  • Warren
  • Somerset
  • Hunterdon
  • Middlesex
  • Mercer
  • Monmouth
  • Burlington
  • Salem

Does BLD affect all beech trees?

While the primary concern in New Jersey is our native American beech (Fagus grandifolia), this disease also targets European beech (F. sylvatica), Chinese beech (F. engleriana), and Oriental beech (F. orientalis).

What impact will BLD have in New Jersey?

The American beech is an essential part of our forest’s ecosystems, providing both shelter and food (beechnuts) for our local wildlife. And with the damage the emerald ash borer has done to the ash population, substantial death in the beech population will further disrupt our forest ecosystem.

WARNING: BLD is not the only disease to keep an eye out for with beech trees, as they also face threats from beech bark disease (BBD). BBD is another fatal tree disease that traces its roots back to the 1890s. Like BLD, there is no known cure for BBD.

Causes of Beech Leaf Disease

Nematodes, microscopic worms also known as roundworms, cause BLD. The nematode Litylenchus crenatae ssp. mccannii (Lcm) is a parasite that feeds on beech leaves. Lcm does not affect the woody tissue, only the leaf buds and leaf tissue.

Lcm overwinters in the infected buds and lays eggs in the late winter or early spring. Observation has even shown these eggs survive in aborted buds. The nematodes reach a juvenile stage by the middle of summer, and the infection is most prominent at the end of the summer season and in early fall. As the winter approaches, the adults exit leaf tissue and migrate to buds to begin the cycle in the following year.

Research has shown that the adults spread at least 38 feet from infected beech trees due to wind and precipitation. Rainfall also transports Lcm nematodes from the higher portions of the canopy to the lower portions. Beech blight aphids (Bryylloprociphilus imbricator) and several bird species may carry nematodes to new trees and areas.

Beech leaves demonstrating symptoms of beech leaf disease in Chester, New Jersey.

Looking up at beech leaves allows you to more easily identify the trademark dark banding that is the tell-tale sign of beech leaf disease infection.


Symptoms of Beech Leaf Disease in New Jersey

The first apparent symptom of BLD is dark stripes or bands on the lateral veins of beech leaves. Typically, you will notice these signs during bud break in the spring, and they may be unevenly distributed in the lower canopy. To help spot BLD, look up at leaves, as it is easier to notice the banding against a bright background like the sky.

As the disease progresses, other symptoms will appear, such as:

  • Heavier banding on leaves
  • Smaller leaves
  • Leaves will have a leathery texture
  • Leaves appear crinkled, deformed, or shriveled
  • Leaves take on a copper color
  • Premature leaf drop
  • Aborted bud development
  • Thinning canopy

The U.S. Forestry Service reports that tree mortality typically occurs within two to seven years and that the disease is more common in smaller trees.

PRO TIP: While we love our trees in New Jersey, they are unfortunately attacked by numerous pests and diseases. Check out some of our other articles on the topic of pests and diseases, such as:

Managing Beech Leaf Disease in Morris County, NJ

As of June 2024, there is no known cure for BLD, and mitigation options are scarce. Researchers continue to experiment with new techniques and treatment options, with some success in improving a tree’s health.

While we don’t have a silver bullet to stop BLD, there are some methods we can use to treat trees with the disease.

Keep Your Trees Healthy to Help Them Fight Off Diseases

Trees get stressed, just like us. When under stress, they aren’t as capable of resisting diseases. Follow these standard tree care practices to reduce tree stress and keep them healthy:

  • Provide water during a drought.
  • Apply a two-inch layer of mulch around your tree. Avoid piling it around the trunk; the root collar (where the trunk flares out at the base) should always be visible.
  • Avoid mowing under the tree and eliminate foot traffic in the area to prevent soil compaction.
  • Prune your trees to eliminate dead or diseased branches and those that rub against each other.
  • Apply fertilizer if a soil test indicates a nutrient deficiency.

Report Any Possible Sightings of Beech Leaf Disease

If you suspect BLD in your yard or the nearby forest, you should first have an arborist diagnose your trees and determine if BLD is present. Once you’ve confirmed a sighting, you should report it to the state government.

Residents can report symptoms and possible BLD by using the Tree Health Survey App or by directly contacting the New Jersey Forest Service.

Avoid Transplanting Beech Trees

While there are no quarantines at nurseries, we recommend being careful about transplanting beech trees from areas with known infections. Though BLD is all around us in the Morristown area, you still don’t want to bring in beech trees from elsewhere that might further propagate the disease.

The team at Alpine injecting a treatment mixture into a beech tree infected with beech leaf disease.


Phosphite Products May Help a Tree with Beech Leaf Disease

READ BEFORE TRYING THIS: While there are some experimental methods for controlling BLD, they have yet to go through extensive study and research. Arborists do not fully understand the effectiveness of these treatments nor the long-term impact they may have on beech trees.

In 2022, the University of Rhode Island reported on tests from Ohio that indicated using phosphite can help a tree fight off BLD. The tests applied the phosphite fertilizer at the drip line of infected saplings between two and four inches in diameter at breast height (DBH). The test subjects showed better health and reduced symptoms five years later than untreated trees.

While a tree care professional would be happy to help you with the application, if you want to do it yourself, you’ll need to mix two fluid ounces of PolyPhosphite-30® with 14 ounces of water for every one inch of DBH. Be careful not to overapply the mixture, as it can harm the tree.

The University recommends a fertilizer application schedule of twice between May and September, with at least one month between the first and second application. To apply the mixture, here are the basic steps to follow:

  • Remove any leaf litter (fallen twigs, branches, or leaves) from the drip line area (the outermost portion of a tree’s canopy).
  • Moisten any dry soil before application.
  • Apply the mixture inside the drip line and avoid applying it to the roots.

WARNING: While many phosphite fertilizers do not require a special pesticide applicator license to apply, those with fungicides do. Always check the label before proceeding.

Thiabendazole Shows Promising Signs for Controlling BLD

Reports from the Rutgers University say Thiabendazole may effectively prevent dieback, reduce leaf symptoms, and control the Lcm population in beech trees.

There is no DIY option for Thiabendazole treatment. Arborists inject it directly into a tree’s vascular system low on the root flare. Most early tests applied Thiabendazole to larger trees between 10 and 22 inches DBH.

Suspect Beech Leaf Disease in Your Trees? Call Alpine Tree for Diagnosis & Treatment

With so many trees at stake, it’s crucial to know the signs of BLD so you can seek treatment. Still, not every tree can be saved, and you may have to remove dead beech trees if the disease appears in your yard. If you catch it early, the team at Alpine Tree can help.

At Alpine Tree, we are monitoring updates on the BLD situation in Morristown and throughout New Jersey. We keep up to date with the latest developments and techniques to best help our community combat this deadly disease. If you suspect BLD, call us at 973-964-7798 or request an estimate online to schedule a tree inspection for BLD diagnosis and treatment recommendations.

Alpine Tree

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