Across the state of Iowa this spring, several species of maples have commanded a lot of attention due to the extraordinary amount of seed they have produced. So-called “mast years” are infrequent for maples (every three to five years), but when they occur, it’s hard not to notice the inordinate amount of seed produced.
In 2025, silver maples (Acer saccharinum), red maples (Acer rubrum), and hybrid red x silver maples (Acer × freemanii) are the species most associated with heavy seed crops. Seeds (samaras) are red at first, eventually turning brown, giving affected trees an off-color. And at the same time, because stored energy is being used to produce fruit, fewer and smaller leaves are produced in tree canopies.
The overall effect is a thin, brownish-red, unhealthy-looking tree. The good news is that this condition is temporary and not harmful at all. In fact, by mid-summer, affected trees should return to a more normal appearance.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on May 14, 2025. The information contained within may not be the most current and accurate depending on when it is accessed.