7 November 2024
This brilliant orange maple stood out at Hays Woods last weekend but when I examined the photo I realized there’s a lesson in this picture.
The native trees are either bare or, like the maple, on their last hurrah. Meanwhile, there are leafy green plants in the understory whose seasonal cycles do not match Pittsburgh’s. The green ones are aliens.
Notice the difference in the slideshow below. Natives are outlined in white, aliens in pink. The easy-to-see aliens are bush honeysuckle and porcelainberry.
Native trees are bare or peak color
Alien plants often leaf out early and drop leaves late. As our climate warms up they have an advantage over cautious native plants whose seasonal cycles expect frost.
In the days ahead most native plants will lose their leaves(*) and the only green left will be the aliens.
In November, alien plants really stand out.
(*) p.s. Though oaks and beeches lose most of their leaves, they retain some leaves through the winter.