From our perspective as plants in the genus *Coreopsis*, we feel it is important to clarify our ecological role. The term "invasive" is a serious designation with specific criteria, generally meaning a non-native species that spreads aggressively and causes ecological or economic harm. Our relationship with this label is complex and varies significantly by species and region.
The vast majority of our species, including the beloved Lance-leaved Coreopsis (*Coreopsis lanceolata*) and Tall Coreopsis (*Coreopsis tripteris*), are native to various regions of North America. We are not considered invasive in our native ranges; in fact, we are celebrated for our ecological benefits. We provide nectar and pollen for bees and butterflies, and our seeds are a food source for birds. Gardeners and restoration ecologists actively seek us out for our drought tolerance, bright blooms, and ability to thrive in poor soils without becoming bullies towards our native plant neighbors.
There is one member of our genus, Plains Coreopsis (*Coreopsis tinctoria*), that requires a more nuanced discussion. This species is also native to North America, found predominantly in the central United States and parts of the West. However, due to its prolific self-seeding and adaptability, it has naturalized well beyond its original historic range. In some states, particularly in the western US, its vigorous seeding habit has led to its classification in certain contexts. For example, the state of Washington lists *Coreopsis tinctoria* on its Non-Regulated Noxious Weed List. This is a monitoring list for plants that demonstrate invasive potential. It is not banned or required to be controlled, but its presence and spread are noted with caution.
It is crucial to understand that even a native plant can exhibit "weedy" or aggressive tendencies when moved into a region where it did not historically exist. A plant from the eastern prairies may behave differently when introduced to the west, lacking the natural competitors, herbivores, or diseases that kept its population in check in its home territory. Therefore, while a *Coreopsis* species may be a perfectly well-behaved native in one state, it might be viewed with more suspicion if it is introduced into a state far outside its native range and begins to spread enthusiastically into wild areas.
Many of us are grown in gardens as cultivated varieties (cultivars) bred for specific traits like double flowers or unique colors. These cultivars are often sterile or produce significantly less seed, rendering them incapable of becoming invasive. The primary concern for gardeners is usually deadheading (removing spent flowers) to prevent any species with high seed viability from self-sowing excessively within the garden bed itself. This is a matter of garden maintenance, not ecological invasion.
