If you’ve looked up at your beech trees and noticed strange, dark stripes on the leaves, it is a sign that they are dealing with a deadly disease: beech leaf disease. Beech leaf disease has existed in Northern New Jersey for several years and threatens to obliterate our beech population. Learn more about this disease, how to spot it, and what you can do to save your trees from it.
Key Takeaways:
- Beech leaf disease (BLD) is a fatal condition affecting American and European beech trees in Northern New Jersey.
- Microscopic foliar nematodes that feed exclusively on beech leaves cause the disease and can kill trees within 2-7 years.
- The disease first appeared in New Jersey in 2020 and has distinctive symptoms, including dark bands on leaves, thinning canopy, smaller leaves, early leaf drop, and leathery-textured foliage.
- With approximately 12 million beech trees in New Jersey, the spread of BLD threatens to devastate local ecosystems since beech trees provide essential food and shelter for wildlife.
- While there is no cure for BLD, promising treatments include the fungicide Arbotect 20-S (administered via trunk injection) and preventative measures such as proper fertilization, pruning, watering, and mulching.
- Don’t preemptively remove beeches – monitor for symptoms, consider planting alternative species, and properly dispose of infected tree debris on-site to prevent spreading the disease.
What Is Beech Leaf Disease?
Beech leaf disease (BLD) is a fatal tree disease affecting various beech tree species. The main concern in Northern New Jersey is the American beech (Fagus grandifolia). However, the disease also affects non-native trees homeowners have planted in their yards, including:
- European beech (F. sylvatica)
- Chinese beech (F. engleriana)
- Oriental beech (F. orientalis)
The first confirmed case of BLD was in Ohio in 2012. New Jersey was able to avoid a positive case for eight years, but everything changed for our beech trees in 2020.
Northern New Jersey was the epicenter of the initial outbreak of BLD. Bergen and Essex counties were the first two counties with a confirmed case of the disease in 2020. Since then, the disease has spread throughout the rest of Northern New Jersey and the central part of the Garden State.
Photo courtesy of Sandy Wolkenberg; Beech Leaf Disease (Litylenchus crenatae)
Symptoms of Beech Leaf Disease
One stroke of good luck when dealing with BLD is that it has pronounced symptoms. The first thing you will notice is dark stripes or bands on the leaves. These are visible during bud break, and you are more likely to see them on the lower portions of the canopy than the top. To more easily identify BLD, look up at the tree when the sun is out, as it is easier to see the banding this way.
Further symptoms include:
- Thinning canopy
- Smaller leaves or lack of bud development
- Early leaf drop
- Leathery feeling and copper-colored leaves
When looking for symptoms, examine your smaller beeches first. They are more likely to have an infection than larger ones.
How Does Beech Leaf Disease Spread?
Researchers have identified the microscopic foliar nematode Litylenchus crenatae ssp. Mccannii (Lcm) as the cause of BLD. They are parasites that feed exclusively on beech leaves, ignoring the tree’s woody parts.
Researchers are still trying to learn more about Lcm, including its origin, as many believe it is non-native to North America. Foliar nematodes are typically not a significant problem for trees, and Lcm is the first one observed that kills trees.
Lcm will attack your beeches in mid-summer and autumn and feed on the leaves. If the nematode presence is high enough, you’ll notice banding in the fall. If the number of Lcm is low, banding may not become apparent until the spring. When cold weather approaches, Lcm will overwinter on the leaves and lay eggs at the end of the winter or in early spring. They then repeat the process and colonize your tree further.
The nematodes may reach your tree with help from birds or insects unwittingly carrying it to the leaves. Wind and rain can also carry adults to nearby trees to infect them with BLD.
Depending on the severity of nematode presence in your tree, it may die within two to seven years.
The Growing Threat of Beech Leaf Disease in New Jersey
Since its first detection in our area, BLD has produced a lot of anxiety in arborists and foresters. Experts estimate there are around 12 million beech trees in New Jersey when accounting for forests and urban areas. American and European beech are the most common in our area.
Beeches are a pillar of Northern New Jersey’s ecosystem, and losing countless trees to BLD will have severe consequences. Beech nuts are a popular food source for bears, foxes, small mammals, and many birds. Many insects and birds utilize the trees for shelter. As the population declines, these species will likely struggle as they attempt to find alternative options.
“Wildlife is not the only thing that will notice the impact of losing beeches. A lot of homeowners in Northern New Jersey may have beeches on their property or live near a forest full of them and not even notice it. But they will once they start seeing these trees die from beech leaf disease.” – Casey Walentowicz, Aspen Tree Owner and ISA Certified Arborist
At Princeton, one of the most famous landmarks of New Jersey, the caretakers of their trees have begun to worry that the beeches will not survive. Princeton has thousands of beeches at risk of dying from BLD.
PRO TIP: Want to learn more about BLD and how it might change our ecosystem? Check out this lecture from Jean Epiphan of the Rutgers Extension Service as she details what’s at stake as it spreads throughout New Jersey.
How to Treat and Prevent Beech Leaf Disease
Since 2012, researchers have been trying to better understand BLD and the Lcm that causes it. While there is no cure for BLD, there are several treatment options available that have shown effectiveness. However, arborists are still developing their understanding of these treatments and their long-term effects.
Keep Your Tree Healthy to Lower the Risk of BLD
As with most diseases, one of the best things you can do for your trees is to keep them unstressed and healthy. Some things we recommend to protect your beech trees include:
- Provide fertilizer if a soil test indicates a deficiency of nutrients. Studies have shown phosphite fertilizer has been effective at suppressing BLD by limiting nematode activity on trees.
- Have a professional perform tree pruning to increase tree health.
- Provide supplemental water during a drought or period with little rainfall.
- Apply a two to four-inch layer of mulch around your tree.
Treating a Tree with Beech Leaf Disease
There have been several proposed treatments for trees with BLD. One of the leading options comes from testing in Maine, where arborists found the fungicide “Arbotect 20-S” to be effective in treating BLD.
Arborists have used the fungicide to deal with Dutch elm disease. Testing involved treating some BLD-infected trees with Arbotect 20-S and leaving others alone. Initial results showed treated trees showed fewer symptoms than trees without treatment. Thanks to these tests, Arbotect 20-S now has a special label identifying its properties at helping with BLD.
If you have a tree with BLD, an arborist can inject it with fungicides after the leaves fully expand until early August.
Frequently Asked Questions About Beech Leaf Disease in New Jersey
With so much information about beech trees and BLD, it can be hard to keep everything straight. We’ve answered some common questions homeowners in our area have about the disease and how to deal with it.
Should I preemptively remove my beech trees?
With new discoveries about treatments, we don’t recommend removing your beech trees just yet. If you keep beeches on your property, monitor them for symptoms of BLD and have an arborist inspect and treat them as needed.
How can I identify American beech trees on my property?
Some key aspects of the American beech to help with identification include:
- Dense canopy
- Grows beechnuts that are about one inch in diameter
- Golden and bronze fall color
- Simple leaves (a single blade instead of multiple)
- Leaves have teeth and come to a point
Can I still plant beech trees in Northern New Jersey? What are some alternatives?
At this time, we recommend planting alternatives to beeches since BLD is so widespread in Northern New Jersey. Some other trees we recommend planting include:
- Hornbeams
- Maples
- Birches
If I have to have my tree removed because of BLD, what should I do with the debris?
Do not move any of the debris from a tree with BLD to other areas. You may spread the disease to a new neighborhood and harm their beech trees. Instead, we recommend chipping or burning the wood.
Beech Leaf Disease Is Spreading – Aspen Tree Can Help
When you notice the black bands on beech leaves, you need to act promptly to protect your trees. Fast action and treatment will give them a better chance of surviving beech leaf disease. When you want to ensure someone does the treatment right, trust the experts at Aspen Tree.
The team at Aspen Tree is keeping up with all the latest developments in BLD and how to treat it. We can help keep your beech trees alive or remove them if the infection is too severe. Call us today at 201-939-8733 or request a quote online.
