invasive plants: the ongoing battle

Garlic mustard. iStock

Invasive Plant Control, a Nashville, Tennessee-based company, finished this year’s $20,000 invasive plant control project in Twin Hills Park. The final tally came to eight acres cleared, two more acres than the original contract called for. Areas that could not be cleared mechanically because of the proximity of the weeds to desirable native trees, were trimmed back as much as possible. Phil Avolio, Mt. Lebanon’s Facilities and Parks Coordinator, was pleased with the result.

“The company was respectful to everyone they came across, and even shut the machine down several times to explain the operation and how important it is to the health of the remaining canopy to concerned park users,” Avolio says.

Fighting the invasives is an ongoing battle. A lack of natural predators and diseases means the plants can quickly displace native plants. Some of the most common invasives in Mt. Lebanon are Japanese knotweed, wild grapevine, garlic mustard, hairy bittercress, English Ivy and oriental bittersweet.

Some plants intended for ground cover, such as Japanese honeysuckle vine and euonymus are invasive. When landscaping plants get into the parks, they grow unchecked and displace native plants. Many of these plants have found their way into parks. Once established, they are very difficult to remove.

Here are some ways to stem the flow of invasives in the parks:

Dispose of plants and seed pods in the trash. Never dump yard waste in public parks.

Where possible, use native and non-invasive plants in your gardens.

If your property abuts a park, refrain from using landscaping plants that may spread out of your yard and into the park.

And if you want to be more hands-on in the fight against invasives, you can join Mt. Lebanon Nature Conservancy volunteers working in the parks between 9 and noon, the third Saturday of each month. Locations are identified under Upcoming Events on