keep an eye out for invasives

In Mt. Lebanon, as elsewhere in the region, we have seen a rapid increase in the number of invasive plants cropping up in our yards and parks. Invasive plants can out-compete native plants because of the lack of predators and diseases that would keep them in check in their native environment. Information concerning invasive plant identification and methods of controlling them are readily available on the Internet. Some of the most common culprits in Mt. Lebanon are garlic mustard, hairy bittercress, Japanese knotweed, English ivy and oriental bittersweet.

Both garlic mustard and hairy bittercress are herbs that produce an abundance of seeds and therefore spread quickly. You can remove them easily by hand, if you catch them before they drop their seed. In addition to weeds, some plants we buy from nurseries and plant to beautify our yards can become invasiave. Prime examples are ground cover plants: English ivy, vinca minor, Japanese pachysandra, Japanese honeysuckle vine and euonymus. When these plants spread where they are not wanted in our yards, we weed them out. The same does not apply to our parks in Mt. Lebanon. When landscaping plants get into the parks, they grow unchecked and displace native plants. These groundcover plants have all found their way into our parks. Once established, they are very difficult to remove.


Garlic Mustard, above, and hairy bittercress, below, are two of the most common invasive plants found in Mt. Lebanon gardens and parks. Left unchecked, they can spread quickly. Pull them before they go to seed and put them in the trash; do not compost them.

In order to protect our parks, please take the following precautions:

• Where possible, use native or non-invasive plants in your gardens.
• Put invasives and their  seed pods in the trash—don’t compost them.
• Never dump yard waste in public park areas.
• Keep landscaping plants controlled within the boundaries of your yard.
• If your property borders on a park, refrain from using landscaping plants that may spread into the park.

If you have questions, check the invasives link on Mt. Lebanon Nature Conservancy’s  website,, or email If you want to do something more hands-on, join the Nature Conservancy volunteers working in Mt. Lebanon parks between 9 a.m. and noon, the third Saturday of each month. Location is identified under Upcoming Events on