Invasive Plants

Many of the plants we see in our yards are not native to the mid-Atlantic region. Some of these plants are not good neighbors, and refuse to stay in our yards, with disastrous consequences.

Privet eliminates the forest understory. Photo: Nava Tabak, Invasive Plant Atlas of New England,

Privet eliminates the forest understory. Photo: Nava Tabak, Invasive Plant Atlas of New England,

Invasive plant species not only threaten our natural areas, they may also invade your garden. Landscape plants that seed freely can cause extra work. Seedlings must be weeded out before they take over and displace plants that were painstakingly planted in your garden. Plants such as bamboo can spread quickly from your garden onto other people's property, decreasing their enjoyment of their property and their enjoyment of having you as a neighbor.

Just because a plant does not seem unmanageable in your garden does not mean that the seeds from your plants are not spreading. The fruits on plants, such as barberry or mile-a-minute, are eaten and spread by birds, causing infestations in faraway places.

Mentioned here is a short list of the plant species causing habitat loss for native plants and animals. Some invasive plants were imported and planted for erosion control or as ornamentals before their detrimental effects were fully realized, some came in as 'hitchhikers' with the movement of people and goods. They can also be spread through hiking and camping activity. Birds and other animals also spread seeds within a region as fruit passes through their digestive systems and seeds cling to feathers or coats.

The major problem with all of the invasive plant species is their lack of any natural controls, have aggressive growth patterns and reproduce rapidly and prolifically. Combined with their lack of nutritional and habitat quality for native wildlife, they are very disruptive in the forest and watershed ecosystems on which we all depend. In our mid-Atlantic region, find out more at:

Plant Invaders of Mid-Atlantic Natural Areas.
National Invasive Species Information Center - Plants

Already in the county:
Butterfly bush (Buddleja davidii)
Japanese stilt grass (Microstegium vimineum)
Mile-a-minute vine (Persicaria perfoliata, formerly Polygonum perfoliatum)
Japanese barberry (Berberis thunbergii)
Japanese spiraea (Spiraea japonica)
Exotic bush and vine honeysuckles (Lonicera spp.)
Oriental Bittersweet (Celastrus orbiculatus)
Garlic Mustard (Alliaria petiolata)
English Ivy (Hedera helix)
Chinese and Japanese wisteria (Wisteria sinensis and W. floribunda)

On our border:
Wavyleaf basketgrass (Oplismenus hirtellus ssp. undulatifolius)

Worth watching:
Cogongrass (Imperata cylindrica)

For additional information:
i Conserve Pennsylvania Tree Protection and Conservation
Invasive Plants in Pennsylvania
Landscaping with Native Plants
Mid-Atlantic Ecological Landscapes Partnership
Management plans - USDA

For suggestions regarding invasive plant control:
Penn State Pest Management
Weeds Gone Wild - Fact sheets and information on control by species
Penn State Natural Resources Extension - Fact sheets on invasive plant and insect species

For information on other plants to use, visit Native Alternatives

Return to Pest Pages

Gypsy Moth

— by Diane Oleson, M.S. — last modified March 5, 2012 11:12 AM

Gypsy moth is a cyclic insect that has been a problem in York county and will be again.

Invasive Tree Pests

— by Diane Oleson, M.S. — last modified March 5, 2012 11:23 AM

Learn about Emerald Ash Borer, Asian Longhorned Beetle, and Thousand Cankers Disease and other tree issues.

Aquatic Invasive Species

— by Diane Oleson, M.S. — last modified December 2, 2011 4:28 PM

Invasive species are not restricted to the land. Many invasive species that are problems in our water bodies are also part of our homes, as pets; in ponds or water gardens; or are moved via our recreational activities.

Native Alternatives

— by Diane Oleson, M.S. — last modified March 5, 2012 12:20 PM

Consider the use of native plants in your yards and gardens instead of non-native plants. Here are resources to assist gardeners in making more eco-friendly selections.

Home and Garden Pests

— by Diane Oleson, M.S. — last modified March 5, 2012 12:29 PM

Here are some unwelcome invasive guests common around the house or in your garden.