White Ash

White ash is the large eastern hardwood that produces some of the most vivid and varied fall color in the deciduous tree world, bronze, burgundy, gold, maroon, orange, purple, red, and yellow, sometimes all on the same tree. Native from Nova Scotia west to Minnesota and south to Florida and Texas, it grows as an upright, spreading shade tree that reaches sixty to eighty feet at maturity. The wood is legendary: baseball bats, tool handles, and furniture have been made from white ash for centuries. The compound leaves with five to nine leaflets provide filtered shade in summer.

The conversation about ash trees has changed dramatically in the past two decades because of the emerald ash borer, an invasive beetle from Asia that has killed hundreds of millions of ash trees across eastern North America and is moving west. The emerald ash borer has been detected in Oregon and is expected to reach Western Washington. When it arrives, every untreated ash tree in the region will be at risk. If you have an existing white ash, it is worth monitoring for EAB and considering preventive treatment when the borer is confirmed in your county. If you are choosing a new tree, planting ash right now is a gamble. The fall color is magnificent, but the existential threat is real.