As you see, our American mountain ash trees (aka American rowan trees) have been bursting out all over with berries this fall. According to a popular folktale, an abundance of berries on these trees means a severe winter is coming because the trees sense the future weather and have evolved to provide extra food for birds and other wildlife.
I hate to upset anyone who believes in such helpful compassion of trees, but mountain ashes actually are very poor predictors of the weather, according to the scientific literature. The usual cause of a big crop of berries on these trees reportedly has to do with the good past, not the bad future. When the previous spring had adequate moisture (rain, fog, etc.) and the summer had plenty of sun, these trees often produce a bumper crop of berries, according to researchers.
Curiously, we’ve been suffering from severe drought this summer and fall, but the mountain ashes don’t seem to be worried about that either. (Images taken in Brooklin, Maine, on September 10, 2025.)