Peter Crane, the Yale University botanist who wrote an entire book on ginkgoes, said, “it often is that a large portion of the leaves — which are brimstone yellow in the autumn sunlight — a huge proportion of those leaves come down on one night,” in a 2015 interview with Margaret Roach, who hosts a gardening public-radio show and podcast.
Crane’s book says that the ginkgo has “the most synchronized leaf drop of any tree I know.”
Most trees develop protective scarring in their stems over the course of a few weeks, and leaves fall off sporadically. “But ginkgoes form the scar across all their stems at once,” the Atlantic wrote. “The first hard frost finishes severing every leaf, and they rain to the ground in unison.”
While the Washington-area ginkgo trees are denuded, they’ve padded sidewalks and lawns in a carpet of green and a few hints of yellow.
Capital Weather Gang’s Ian Livingston, who has observed these trees over the years, said this year’s leaves fell when they were “on the greener side” compared with some other seasons. That’s because the hard freeze hit early in November, before the foliage had progressed to peak yellow.
“[It’s] unfortunate since they are rather pretty at peak,” Livingston said. “I’d say it probably had another week or so till peak. They are usually one of the later trees to reach peak.”
See more photos of the ginkgo leaf-drop around the region below.