Executive Order 13112 defines an invasive species as “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.” The National Invasive Species Management Plan (NISMP) further defines an invasive species as “a species that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health.”

[Invasive Species Definition Clarification and Guidance White Paper, Submitted by the Definitions Subcommittee of the Invasive Species Advisory Committee (ISAC), approved by ISAC April 27, 2006 ]

For more information:

National Invasive Species Information Center

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Why are invasive species “bad”?

• Reduce native diversity by competing for resources, such as space, sunlight, water and minerals.
• Alter soil conditions by secreting chemicals that inhibit the germination or growth of other species
• Alter nutrient cycling by changing the amount, composition, or rate of decay of leaf litter.
• May hybridize with native species.
• Disrupt natural communities and change habitat structure for other organisms such as birds, mammals, turtles, fish and frogs.

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Voluntary Codes of Conduct for the Gardening Public 

• Ask for only non-invasive species when you acquire plants
• Seek information on what species are invasive in your area
• Do not trade plants if you know they are species with invasive characteristics
• Request that nurseries promote, display and sell only non-invasive species
• Help educate your community and other gardeners
• Seek the best information on control of invasive plant species and organize neighborhood work groups to remove invasive plants
• Volunteer at gardens and natural areas to assist ongoing efforts to diminish the threat of invasive species
• Participate in early warning systems by reporting invasive species your observe in your area

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