EarthTalk – How does banning invasive plants affect their spread?

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Roddy Scheer & Doug Moss

Dear EarthTalk:
Has banning the sale of invasive plant species slowed their spread?
Maury Turner, Lebanon, NH

According to the United States Forest Service, invasive plant species are defined as plants that are both non-native to an ecosystem and have the potential to harm it either environmentally or economically. These invasive species are often spread by birds, wind, or even unintentionally by humans. These alien species can survive in specific ecosystems because they produce large amounts of seeds and thrive on disturbed soil.

Invasive species have significant negative impacts on specific habitats and the environment. These species compete with native species for resources while also decreasing plant diversity, destroying habitat, and leading to degraded water quality and increased soil erosion. Analysts estimate that invasive species have cost over $1.288 trillion globally over the last half-century.

Three seedling plants, each at different heights showing stages of growth. — © iStock - ArtRachen01

Recently, the state of Washington banned the sale and distribution of English ivy, an invasive species. For many environmental activists, this was cause for celebration. Melanie Weinecke, a park volunteer from Seattle, told NBC affiliate King 5 News in July of 2025 that she was happy about the new legislation as English Ivy is choking out trees and creating “sick forests” around the region.

Virginia is also another state that has passed legislation that limits the ubiquity of invasive species. During the 2025 General Assembly, one bill requires that sellers label invasive species at the point of sale. While this law will not be enacted until January 2027, proponents say that it will allow customers to make informed decisions about plants that could pose a real threat to the community and ecosystem.

While the banning of invasive species could prove to slow the spread in the future, current research shows that widespread availability of these species makes it difficult to regulate them. A 2021 study done in the Journal of Frontiers of Ecology and Environment found that 61% of identified invasive species were still sold in the United States. This shows that legislation may not always be effective in limiting the damage caused by invasive plant species.

Moreover, the lack of consistent regulation across states limits the goals of banning invasive species. Even if one state enacts legislation, other states may continue to allow the sale of a certain species.

Researchers say that there is a necessity for coordinated action against invasive plant species and education around the harms of introducing them to specific habitats and communities. This means increasing outreach to growers so that they understand the potential implications of certain plant species and raising consumer awareness.

Other next steps come from citizen action. The U.S. Forest Service encourages people to avoid picking noxious weeds, drive only on established roads away from harmful weeds, remove weed seeds from pack animals, and avoid picking and transferring unidentifiable wild flowers.