National Invasive Species Awareness Week (February 23-28) kicks off ahead of the spring weed onslaught.

Like many others who struggle to deal with invasive species, we are constantly fending off the unwanted advances of two offenders on environmental groups’ hit list: a stinky towering specimen of the seemingly hell-spawned Tree of Heaven, which from the safety of the neighbors’ property continually rains down thousands of seeds onto our lawn and garden, keeping me on constant pull patrol; and the bamboo-like Japanese Knotweed, which has spread like wildfire along our fence line, only kept in check by the large concrete garage foundation.
Some non-native plants are virtually harmless (the vegetables and herbs in most gardens come from elsewhere) while others are downright destructive—the estimated damage from invasive species worldwide totals more than $1.4 trillion, or 5 percent of the global economy.
But as the Weed Science Society of America (WSSA) points out, much more than the economy is at stake. Invasive species can cause skin irritation, trigger allergies, poison pets and livestock, clog waterways, and out-compete and displace edibles, ornamentals and desirable native plants.
Lee Van Wychen, Ph.D., director of science policy for the WSSA, says awareness is key to managing invasive species infestations. The organization suggests contacting your county extension office and the National Invasive Species Information Center to learn more.
The Nature Conservancy, which works to prevent and control invasives in all 50 states and more than 30 countries, offers some ways you can help to prevent their spread:

• Make sure the plants you buy from local nurseries are indigenous to your area, since many garden centers still sell invasive exotic varieties from Europe and Asia.
• Clean your shoes, boots and clothing before and after walking and hiking in a new area to get rid of hitchhiking weed seeds and pathogens.
• Volunteer at a local park, refuge or other wildlife area to help remove invasive species.
• Educate others about the threat invasive species pose

For more information (must-read books on the topic)
How to Eradicate Invasive Plants by Teri Dunn Chace
The Midwestern Native Garden: Native Alternatives to Nonnative Flowers and Plants (An Illustrated Guide) by Charlotte Adelman
Resources for finding naturally low-maintenance native plants for your area
“What to Plant” map by Douglas Tallamy, author of Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens
Find Native Plants, run by Carole Sevilla Brown of Ecosystem Gardening
—Shannon Roxborough
Shannon Roxborough is the founding editor of Garden Variety. He lives in the snowiest reaches of Zone 6a.
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