Yarrow Native vs Naturalized - Ask Extension
Hello!
I am curious about the native status of Common Yarrow. I am aiming to primarily plant native species and have received conflicting informati...
Knowledgebase
Yarrow Native vs Naturalized #938604
Asked July 08, 2026, 6:46 PM EDT
Hello!
I am curious about the native status of Common Yarrow. I am aiming to primarily plant native species and have received conflicting information from multiple different official sources.
The Extension classifies it as a native on this page: https://extension.umd.edu/resource/deer-resistant-native-plants/
The Maryland Biodiversity Project calls it non-native here: https://www.marylandbiodiversity.com/species/81519
But then the sources for the Maryland Biodiversity Project also says it is native in MD: https://beta.floranorthamerica.org/Achillea_millefolium
If it is actually naturalized, how does that compare to invasive species? Is it almost like it is post-invasive as it has now integrated fully into the ecosystem?
Baltimore County Maryland
Expert Response
To our knowledge, ecologists have not settled that debate yet, so as you noticed, some resources say Achillea millefolium is native to North America while others say it's introduced/naturalized. To complicate matters, Maryland Biodiversity Project lists Achillea millefolium subspecies borealis, also listed as just Achillea borealis, as native in Maryland, with the implication (on the Achillea millefolium species page, as you saw) that "true" Achillea millefolium is non-native.
Naturalized plants are those which are non-native within the ecosystem in question and which were originally introduced by people, but which have established and reproduced on their own. Invasive plants are a step further along that spectrum in the sense that their spread causes significant ecological or human/economic harm. Invasive plants are more disruptive to the environment compared to a naturalized species that may be present but which isn't taking over habitats or displacing as many native species.
Miri
Naturalized plants are those which are non-native within the ecosystem in question and which were originally introduced by people, but which have established and reproduced on their own. Invasive plants are a step further along that spectrum in the sense that their spread causes significant ecological or human/economic harm. Invasive plants are more disruptive to the environment compared to a naturalized species that may be present but which isn't taking over habitats or displacing as many native species.
Miri
