Green Ash

Green ash is the most widely planted ash in North America, the fast-growing, adaptable shade tree that municipalities and developers installed by the millions along streets, in parks, and around new subdivisions from the 1960s through the 2000s. It grows fifty to sixty feet with a spreading, rounded crown and compound leaves with five to nine leaflets that turn yellow in fall. Native from Nova Scotia to Manitoba and south to Florida and Texas, it thrives in floodplains, river bottoms, and the kinds of heavy, periodically wet soils that defeat pickier species.

The story of green ash is now inseparable from emerald ash borer. Every green ash in North America is a target for this invasive beetle, and the devastation across the Midwest and East has been catastrophic, tens of millions of trees dead, urban canopies hollowed out, municipal budgets shattered by removal costs. EAB has been confirmed in Oregon and its arrival in Western Washington is a matter of when, not if. If you have an existing green ash, learn the signs, D-shaped exit holes, canopy thinning from the top down, bark splitting over serpentine larval galleries, and be ready to make treatment or removal decisions when EAB is confirmed in your county. If you are choosing a new tree, plant something else. The risk is no longer theoretical.