The boxelder tree, scientifically known as Acer negundo, is a widely distributed and adaptable species belonging to the maple family (Sapindaceae). It stands out among other maples due to its unique leaf structure. This tree is common across North America, thriving in various environments. While often considered a fast-growing and resilient tree, it also presents specific characteristics and concerns for homeowners and land managers.
How to Identify a Boxelder Tree
Identifying a boxelder tree involves observing several distinct features, particularly its leaves, bark, and seeds. Unlike most maples, the boxelder has pinnately compound leaves, meaning each leaf stalk consists of multiple smaller leaflets. These leaves have three to five leaflets, sometimes up to nine, arranged oppositely along the stem. The leaflets are light green, with a paler, grayish-green underside, and their margins are coarsely toothed or somewhat lobed. Young twigs are smooth and green to olive, often with a whitish, waxy coating, and feature conspicuous white lenticels.
The bark of a boxelder tree changes with age, starting as light brown to pale gray with shallow, interlacing ridges when young. As the tree matures, the bark becomes more deeply furrowed. Female boxelder trees produce distinctive winged seeds called samaras, which appear in V-shaped pairs and hang in drooping clusters. These samaras ripen in the fall but remain on the tree through the winter, making them a useful identification marker during colder months. The tree’s overall shape is irregular, with a short, crooked trunk that divides into multiple spreading branches, forming a broad, uneven crown.
Growth and Life Cycle
Boxelder trees are known for their rapid growth rate, especially during their first 15 to 20 years, with annual shoots extending two feet or more in a year. This fast growth contributes to a relatively short lifespan, typically 60 to 75 years. The wood of the boxelder is light, soft, and weak, which makes it brittle and prone to breakage, particularly during wind or ice storms.
This species is highly adaptable and can be found across a wide range of habitats, from Canada to Guatemala. It grows in moist, wooded areas like river bottoms, floodplains, and near streams, but also tolerates drier upland sites. Boxelder trees are resilient, thriving in diverse soil types, including heavy clays, sandy loams, and even poor, disturbed urban soils. They are also tolerant of drought and cold conditions, contributing to their widespread presence. Boxelder trees are dioecious, meaning individual trees are either male or female, with flowers appearing in early spring, and seeds ripening in late summer or fall.
Common Concerns and Management
One of the most recognized concerns associated with boxelder trees is the presence of boxelder bugs (Boisea trivittata). These insects primarily feed on the seeds and leaves of female boxelder trees. While their feeding causes little significant damage to the tree itself, boxelder bugs become a nuisance when they congregate in large numbers on buildings during the fall, seeking warm places to overwinter. They do not bite humans or transmit diseases, but they can stain surfaces if crushed.
The tree’s weak and brittle wood leads to issues with falling branches, especially in severe weather, creating a landscape maintenance challenge. Female trees also produce abundant samaras that fall and create a mess on lawns and sidewalks. Boxelder trees are susceptible to certain diseases, including leaf anthracnose, bark canker, and trunk heart rot, which impact their health and appearance. Due to these characteristics, boxelder is considered a less desirable landscape tree in urban settings.
Management involves regular pruning to maintain structural integrity and remove dead or damaged limbs. Pruning can be done in late winter before new growth or in late spring after leaves emerge. For nuisance boxelder bugs, sealing cracks around homes helps prevent indoor infestations.