The record September heat spell has broken, but dry conditions continue to affect trees’ color this autumn at The Morton Arboretum. Fall color is developing faster than normal but in unusual patterns, because plants are stressed by the dry soil. Some of our woody plants, such as sumacs, buckeyes, and Virginia creeper, are turning red at their normal times, but many plants turning color and dropping their leaves early.
Bloom in the Schulenberg Prairie is generally on schedule, with asters bearing blue and purple flowers. Fall asters also are blooming in the East Woods. Sugar maples in the woods are turning orange at the tops where leaves are exposed to the sun, but some maples, stressed by the lack of water, are beginning to lose leaves. Trees and shrubs that are turning color and dropping leaves early include redbud, ironwood, elm, white ash, black walnut, Freeman maple, coffeetree, corktree, honey locust, witch-hazel, tree lilac, katsura, zelkova, and pawpaw. How long fall leaf color will last and how intense the colors will be depends on the weather. This week, the best areas to view fall color are the Maple Collection (Parking Lots 7,8, and 14); the Sumac and China collections (Parking Lot 18); the East Woods (Parking Lots 8 to 13); the area around Lake Marmo (Parking Lots 27 and 28); and the Schulenberg Prairie (Parking Lot 25).