How did the invasive weeds get here?
Many flowering invasives such as herb Robert and morning glory were planted by gardeners. Invasive knotweeds and English ivy were planted by landscapers for their ability to grow quickly and create natural fencing barriers. Non-native blackberry was cultivated for its fruit. Plants like the St. John’s wort were introduced for their medicinal benefits. Others such as Eurasian watermilfoil were accidentally brought across the oceans in shipments or carried on ship ballasts.
Whether they hitched a ride accidentally or were brought here on purpose, all of the invasive plants we remove at work parties have aggressively spread far beyond the expectations of those who originally brought them. The effects of this spread, unchecked by natural predators or conditions, now cause a major threat to the health of our native habitats here in the Pacific Northwest. To help restore these habitats to health in a city park or natural area near you, improving environmental functions such as stormwater control as well as caring for our valuable public greenspaces, volunteer with one of the Green City Partnerships.