Emerald ash borer (EAB) is a serious threat to valuable ash trees found in home landscapes. Because of the aggressive nature of EAB, trees in infested areas that are to be saved will likely require treatment throughout their lives.
The cost of treatments can be considerable. This publication provides guidelines to help you evaluate your tree, discusses options for treatment, and provides information on replacing ash trees with other species.
Should My Tree Be Treated?
- Treatment is recommended when EAB is known to be within 15 miles of your location.
- Treating trees beyond 15 miles will likely provide little or no benefit to the trees and will result in unnecessary exposure of the environment to pesticides.
- State and federal agencies monitor EAB infestations and will provide updates on infestations in Nebraska.
- Visit the Nebraska Forest Service for information about when to begin treatments (www.nfs.unl.edu/EAB.asp).
Infested with EAB
- Trees already infested with EAB are treatable if the damage is not severe.
- Trees with more than 50% canopy loss will likely not recover.
- In some communities, removing infested trees may be mandatory.
Tree Health & Value
- Trees not infested with EAB may still have other health issues.
- Look for extensive branch dieback, sparse foliage, conks (mushrooms) on the trunk or branches, or severe trunk injuries.
- These trees are not good candidates for treatment and may need to be removed for safety reasons.
- A well-placed tree may provide shade for the home, screen an undesirable view, block wind or reduce noise.
- Trees increase property values, improve air quality, and slow stormwater runoff.
- Some trees have high sentimental or historical value.
- The annual economic value of a tree can be a guide to the amount a homeowner might be willing to spend each year on tree care, including pest control (see table below).
- Trees growing too close to buildings, fences or sidewalks or under electrical wires may eventually damage these structures or interfere with their functioning.
- These trees should be removed rather than treated for EAB.
- Very small trees are generally easier to treat successfully, but the treatments will cost more over time than removing and replanting with a tree that is resistant to EAB (see page 4).
- Large trees can be more difficult and expensive to treat, but they typically provide more benefits than a small tree.
- Removal and replanting is still an option with large trees, but the cost of removal may be high, and the benefits lost are not quickly regained by the newly planted tree.
- Many insecticides are used to treat for EAB, and each has a different impact on the environment.
- Most are broad-spectrum pesticides, toxic to many organisms, including humans. Check pesticide labels for more information.
- Trunk injections and implants typically have less effect on non-target organisms and the environment compared to soil treatments and foliar sprays because the insecticide is contained within the tree.