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Emerald ash borer

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The larvae of the emerald ash borer are expected to kill most native ash trees in the Midwest, including some 18 percent of the street trees in the Chicago region. The Morton Arboretum’s Community Trees Program and its Plant Clinic can help local governments, community groups, the green industry, and homeowners with information and guidance to cope with this fast-moving scourge and to develop a healthier and more diverse urban forest to replace lost ash trees.


The most obvious signs of EAB attack are dead limbs near the top of the tree. This invasive pest is so aggressive that all native ash trees are at risk, and trees may die within two to four years after they become infested.

All 16 native ash species are susceptible to EAB attacks. In northeastern Illinois, common susceptible ash species include green ash (Fraxinus pennsylvanica), white ash (F. americana), blue ash (F. quadrangulata), and black ash (F. nigra). Horticultural cultivars of these species are also susceptible. Healthy ash trees of any size are vulnerable to attack. The EAB does not attack mountain-ash, prickly-ash, or wafer-ash since they are not true ash or Fraxinus species. (Refer to “Ash Tree Identification” for information on how to identify ash trees).



The Community Trees Program has two handbooks for coping with EAB; 0ne for use by municipal and community leaders, as well as green industry professionals, and the other for homeowners.

For local governments, community groups, and the green industry: EAB and Your Community

For homeowners: Your Ash Tree and EAB