The Arboretum Willow Oak

The second largest tree in Washington is dying, and the people who measured it said so out loud. When Casey Trees brought its 2023 big tree survey to the National Arboretum, this willow oak came in at 287 inches around, beaten by a matter of inches only by the chestnut oak at Battery Kemble. Standing under it, the Arboretum's own arborist put the other half of the story just as plainly: this tree is near the end of its life. The 2012 derecho tore into it, carpenter worms were treated in 2015, and it has been decaying and taking storm damage ever since. Staff are not removing it. They trim the rotting limbs to keep visitors safe and go on buying it time, which is a decision about what an old tree is worth rather than a horticultural one. Its age is folklore. Casey Trees repeats a local story tracing it to the Civil War, but the earliest hard evidence anyone cites is a 1940s photograph showing it already grown and visibly smaller than it is now. Ninety years is the floor, 160 the hopeful ceiling. Two honest notes before you go. Nobody publishes where inside the grounds it stands, so the pin is the Arboretum and the last stretch is a question for staff. And the most recent confirmation of its condition we can cite is August 2023, before the storms of the summers since. If you find it changed, or gone, tell us.