Removing Invasive Species

The emerald ash borer (EAB) is a non-native beetle whose preferred host are native ash trees.

The EAB is a greenish, metallic-colored beetle that is smaller than a penny. It is believed that this insect pest was accidentally introduced into Michigan some years ago as a passenger in shipping crates imported from China.

They were first identified in northwest Ohio in 2003. Midwestern and Eastern State EAB Spread Map

They now occur in 50 Ohio counties, including Hamilton County. Ohio County Infestation Map

Adults lay eggs under the bark of ash trees and the resulting larvae tunnel through the host tree’s living tissue, disrupting the flow of water and nutrients throughout the tree. Once infested with EAB, an ash tree will die in two to five years, having been effectively debilitated by the larval tunneling. 

The emerald ash borer has now been identified and confirmed to be infesting ash trees throughout Great Parks of Hamilton County. The highest levels of infestation were initially recognized in parks on the eastern side of Hamilton County, but the insect (and corresponding tree damage) has since spread across the county. 

Great Parks is continuing to work proactively to meet this challenge in several ways. Approximately 400 specimen ash trees across the park district are being treated with a highly effective injectable insecticide on a two-year treatment interval by trained and licensed Great Parks staff. While expensive, these treatments are expected to preserve these trees indefinitely for landscape value, aesthetic enjoyment and interpretive purposes. 

To insure and improve guest safety, the park district is also actively working to identify and remove dead and dying ash trees from Great Parks areas. Over 18,000 trees, which could pose a potential safety concern, have been systematically identified with GPS locations across Great Parks. To date, over 6,000 trees located in, or near high guest contact areas (trails, roadways, picnic areas, campgrounds and golf courses) have been felled through a combination of contract removal, Great Parks staff removal and natural causes. Great Parks will be aggressively and proactively moving forward with additional tree removal projects each year. 

Where ash tree removal and loss has created a significant effect on tree density and distribution, Great Parks is actively planting new trees through coordinated reforestation efforts. These tree planting projects include a variety of native tree species of varying sizes, with the end goal being a more diverse stand of trees for future generations to enjoy. 

The following agencies provide comprehensive information about Emerald Ash Borer. 

National Emerald Ash Borer Website:
U.S. Forest Service:
Ohio Department of Agriculture:

Contribute to Reforestation

Upcoming Events

  • Don't Move Firewood

    The forests of southwest Ohio have been under attack for years by a variety of non-native plant and insect species, but none have had the dramatic effect on our area as the emerald ash borer (EAB), which can now found in every Ohio county. Unfortunately, another potentially more destructive insect is making its way into our area called the Asian long-horned beetle (ALB), but so far it has not reached Hamilton County. These invasive species are spread mostly by people unknowingly moving infected firewood into uninfected forests and campgrounds. If you want to help save our forests, follow these two simple rules:

    • Don't move firewood. Buy local wood and either burn it on site or leave it behind. Do not take it with you.
    • If you must buy firewood that is not local, buy only wood in its original wrapper bearing a USDA-approved logo, or buy firewood that has been kiln-dried. You can purchase clean firewood at Park District campgrounds and at Lake Isabella Family Fishing Center.

    ALB Quarantine Map
    ODNR ALB Information

  • Invasive Plants

    Great Parks of Hamilton County is working to reclaim prairies, wetlands and forests dominated by invading weeds. Trained staff and volunteers use techniques and equipment that provide the best results with the least negative impact on the environment. Some of the control methods include cutting, hand pulling, mowing, burning, spraying or injecting the safest effective herbicides. Although we will never control all the invasive plants, the results thus far are encouraging. Many acres of park land have been restored to their natural beauty and diversity. 

    Featured here are five of the more than 50 plants considered to be a problem in our natural areas: 

    Bush Honeysuckle (Lonicera maackii) is our most invasive shrub. Bush honeysuckle leafs out earlier than most native plants, thereby shading out everything under its branches including native wildflowers and young trees. In our area, without any natural predators or controls, the bush honeysuckle has become weed enemy number one. 

    Japanese Honeysuckle (Lonicera japonica) was imported to control erosion and to be used as a landscape plant. This vine quickly forms dense patches that climb over and smother extensive areas of native vegetation. 

    Winter Creeper (Euonymus fortunei) is an evergreen groundcover. This tough plant carpets the forest floor, engulfing everything in its path. 

    Garlic Mustard (Alliaria petiolata) is another prolific pest plant that poses a threat to native flowers and wildlife. This plant can out-compete native plants and wildflowers by monopolizing light, moisture and nutrients. The animals that depend on the many species of displaced native plants are also eliminated where garlic mustard prevails. 

    Lesser Celandine (Ranunculus ficaria) may be pretty to behold with its bright yellow flowers, but it wreaks havoc on native species as its thick foliage smoothers out anything trying to sprout from under its leaves. Lesser celandine has even been seen spreading as much as 50 feet up steep hillsides. 

    Some other non-native invasive plants that escape into natural areas include: 
    Autumn-olive (Elaeagnus umbellate)
    Glossy Buckthorn (Rhamnus frangula)
    Common Buckthorn (Rhamnus cathartica)
    Purple Loosestrife (Lythrum salicaria)
    Asian Bittersweet (Celastrus orbicutus)
    Crown-vetch (Coronilla varia
    European cranberry-bush (Viburnum opulus)
    Tree-of-heaven (Ailanthus altissima)
    Burning-bush (Euonymus alatus)

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