How You Can Avoid Spreading Invasive Plant Species

The Short Answer

Invasive plant species — plants introduced to ecosystems where they have no natural competitors or controls — are among the leading threats to native biodiversity worldwide. They outcompete native plants, reduce habitat quality for native wildlife, can alter soil chemistry and hydrology, and cost billions of dollars annually in agricultural and ecological damage. Most invasive plant spread is unintentional, carried by people who don’t know they’re doing it. These practices can significantly reduce the spread.

What Makes a Plant Invasive

Not every non-native plant is invasive. Most introduced plants either fail to establish outside cultivation or coexist with native species without causing significant harm. An invasive plant is specifically one that establishes in a new environment, spreads aggressively without natural controls, and outcompetes native species in ways that reduce biodiversity and ecological function.

Common mechanisms of spread include: seeds carried in soil or attached to clothing, gear, vehicles, or animal fur; plant material transported in garden waste or through horticultural trade; seeds dispersed by birds and other wildlife that eat fruits from ornamental invasives; and seeds that travel in water through drainage systems.

Familiar invasives in North America include kudzu (southeastern US), Japanese knotweed, garlic mustard, purple loosestrife, English ivy, autumn olive, and Japanese barberry. Each arrived through human activity — most through the horticultural trade or deliberate planting.

Purchasing Plants Responsibly

The single largest pathway for introducing new invasive species is the horticultural trade. Many plants currently sold at garden centers are invasive in local or regional ecosystems, but their invasive status may not be labeled and gardeners may not know. Before purchasing any plant:

Research before you plant. Check whether the species is considered invasive in your region. Many state and regional invasive species councils maintain lists of plants known to be problematic locally. Native plant societies and university extension services are reliable resources.

Choose native alternatives. Native plants are adapted to local conditions, support native wildlife, and will not become invasive. For almost every popular ornamental invasive, native alternatives with similar visual appeal exist. Native grasses, shrubs, and flowering perennials often outperform invasives in terms of wildlife value and long-term garden health.

Avoid popular invasives. English ivy, burning bush (Euonymus alatus), barberry, nandina, and Bradford pear are among the most widely sold plants that are invasive in many parts of the United States. Awareness of specific problem plants allows you to make informed substitutions.

Cleaning Gear for Outdoor Activities

Hikers, campers, mountain bikers, hunters, birders, and anyone who spends time in natural areas can carry invasive plant seeds without knowing it. Seeds become lodged in boot treads, on gaiters, in the cuffs of pants, in pet fur, in the tires and undercarriages of vehicles, and on tents and camping gear.

Clean footwear before leaving an area and again before entering a new one. Brush off visible soil and plant material. Washing boots in a bucket of water at the trailhead is more effective; some parks provide brush stations for this purpose.

Check clothing and gear after time in natural areas. Remove seeds, burrs, and plant material before traveling to a new location.

Wash vehicle exteriors when moving between regions, particularly the undercarriage and tire wells, which can carry large amounts of soil and seeds.

Disposing of Plant Material Correctly

Garden waste disposal is a significant pathway for invasive spread. Garlic mustard, Japanese knotweed, and many other invasives can regrow from root fragments or produce seeds that remain viable in compost. Invasive plants should not be placed in compost or yard waste bins unless you are certain your municipal composting facility reaches temperatures sufficient to destroy seeds.

Bag invasive plant material separately for disposal as trash if composting is not appropriate. Do not dump garden waste in natural areas, roadsides, or waterways — this is one of the most direct ways humans introduce invasives to new locations.

Do not release aquatic plants from aquariums or water gardens into natural waterways. Aquatic invasives like hydrilla and water hyacinth have devastated ecosystems where they have been introduced, primarily through release of aquarium contents.

Advocating and Educating

Individual behavior matters, but invasive species spread is ultimately a collective problem that requires collective response. Advocating for policies that restrict the sale of known invasive plants, supporting funding for invasive species control programs, participating in volunteer removal events, and educating friends and neighbors about invasive plant risks all multiply the impact of individual action. Many communities have organized volunteer invasive removal days that provide training, tools, and collective effort toward specific priority species. The scale of invasive spread in most ecosystems exceeds what individual behavior alone can reverse — but collective awareness and action, combined with policy change in the horticultural industry and border inspection programs, can meaningfully slow new introductions and reduce established populations over time.