12/30/2025
Seattle socialite Lillian McEwan led a push to designate Washington as “the Holly State” in the 1920s, rallying thousands of school children to plant to plant English holly in parks and forests. The non-native shrub quickly spread. “It’s up there with Himalayan blackberries as one of the most prolific invasives we deal with,” says Kevin Zobrist, WSU Extension forester.
In natural settings, the holly crowds out native plants, reducing forest diversity and degrading wildlife habitat.
“I liked this story because it shows how a well-intended, but misguided action can have long lasting impacts on forest ecosystems,” says Washington State Magazine writer Becky Kramer of her top story of 2025.
WSU experts warn that English holly, once planted for holiday cheer, has become a fast-spreading invasive species overtaking Northwest forests.