Slowing the Spread of Invasive Plants

The past few centuries have brought an unprecedented flow of people, ideas and plants across the globe. While that has benefitted us (who can imagine gardening without peonies, basil or tulips?), it has also brought challenges.

Some introduced non-native plants simply do too well in their new environment. With no natural pests or predators, these plants go wild. For example, purple loosestrife is spreading at a rate of 250,000 acres per year, choking wetlands with a dense impenetrable mat, and yellow star thistle now dominates millions of acres of northern California grassland.

There are about 50,000 foreign plants and animals in the U.S, according a study conducted by Cornell University. Most of those species aren't a problem. But those that are cause more than $100 billion of damage per year. Moreover, about 400 of the 958 species listed as threatened or endangered under the Endangered Species Act, are at risk primarily due to competition with non-native species.

So what are gardeners to do? Here are a few ideas:

1. Remove invasive plants from your property.
If you find a stand of invasive plants, use the appropriate control measure to remove it. The resources below can help you identify these plants and the proper control.

2. Avoid planting invasive non-native species that could spread from your property.
Some of the same characteristics that make a good garden plant (low-maintenance, drought-tolerance, vigor and pest-resistance), can make it a great weed. So do a little research on these plants first. When in doubt, choose plants that are native to your area.

3. Volunteer for a group that monitors or eradicates invasive plants.
Many garden clubs, local native plant societies and environmental groups monitor and eradicate invasive plants. Call your local university extension service or state department of environmental conservation for more information.

For more information: Invasivespecies.gov is a clearinghouse of information from the federal government.

The Control of Invasive Non-native Plants: A Guide for Homeowners and Gardeners in the Mid-Atlantic Region.

The PLANTS database contains standardized information about plants including identification, distribution and growth information. A list of plants considered invasive can be searched by common or scientific name.

For more articles on improving the world through gardening, see the Garden Activist archive page.