768 Acer negundoCommon Names: boxelder, ash-leaf maple, Manitoba maple Family: Aceraceae (maple Family)
The boxelder is a maple with compound leaves which look more like those of an an ash (genus Fraxinus). The leaves are odd-pinnately compound with 3 or 5 (rarely 7 or 9) leaflets, each about 2-4 in (5.1-10.2 cm) long. Each leaf is borne on the end of a slender petiole that is 2-3 in (5.1-7.6 cm). Box elder leaves are often light yellow when they first come out, aging to pale green in summer, and turning yellowish brown in fall before they drop. Young twigs are bright green. The flowers and fruits are typical maple. The flowers come out in spring just before, or with, the leaves. The fruits are little vee-shaped helicopters, known technically as samaras (and there are lots of them) maturing in the autumn. They are carried in 6-8 in (15.2-20.3 cm) long drooping clusters that often persist on the bare branches late into the winter. Boxelders are dioecious - male and female flowers are on separate trees, and only female trees bear fruit. The boxelder is a smallish tree, rarely exceeding 50 ft (15.2 m) in height. It usually has an irregular shape and a broad, uneven crown. Boxelder branches near the ground and often develops multiple leaders. There are several geographic varieties recognized by botanists, and a handful of cultivars created by gardeners, especially European gardeners. 'Variegatum' is a female clone that has leaves and fruits with broad white margins. 'Flamingo' has pink immature shoots and leaves that age to variegated green and white.
Boxelder, Acer_negundo, is native to much of temperate North America. Its distribution is nearly continuous from southern Saskatchewan to New York, and south to eastern Texas and northern Florida. It is absent from New England and most of the Atlantic Coastal Plain. Elsewhere, boxelder occurs sporadically in the Great Plains, the southwestern U.S. and California. There also are isolated stands of boxelder growing naturally in the mountains of Mexico and Central America. Boxelder is cultivated as an ornamental in Europe and has escaped there and become widely naturalized. This is a tree of bottomlands and moist hardwood forests. It grows along rivers and streams, often in the subcanopy beneath larger maples, oaks, sycamores, hackberries, elms and cottonwoods.
CultureBoxelder is a very fast-growing tree for 10-20 years, then it slows down and rarely lives beyond a century. It can grow to 15 ft (4.6 m) in just four or five years. Boxelder requires a lot of pruning to remove broken and dead branches. Light: Boxelder does best in full sun except in zones 7-9 where it should have some shade at least in the middle of the day. Moisture: Although it grows naturally in moist soils, boxelder does well in dry, upland sites with well-drained soils. It benefits from watering during prolonged dry spells. Hardiness: USDA Zones - . Boxelder is one of the most cold hardy of all broad leaved shade trees. Unfortunately, most of the named cultivars are not as hardy as the species. Most cultivars are listed as hardy only to zone 5 or 6. Propagation: Boxelder produces abundant seeds but they may be difficult to germinate. Seeds should be stratified at 40 F for 2-3 months. Cuttings are easy to root, and this is the only way to propagate the named cultivars.
Boxelder is a fast-growing, weedy little tree. It probably is the most robust and aggressive of all the maples, and suitable for use mainly where most other trees cannot survive. It tolerates air pollution, compacted soils, a wide range of soil pH's, extreme cold, and even brief periods of standing water. Boxelder was commonly planted as a street tree (especially in Europe and the American Great Plains) but it is relatively short-lived, tends to break branches in strong winds and under the weight of ice and snow, and drops a lot of litter. However, a row of boxelders will make a screen and wind break in short order. The wood is soft and weak and not used for much except boxes, crates and firewood.
There are at least 150 species of Acer, and I can't think of another with compound leaves. A more popular small maple for landscape use is the Japanese maple (Acer palmatum) which is available in hundreds of varieties. Another relative is the sugar maple (Acer saccharum) which is tapped in late winter to collect its sap from which is made maple syrup.
Steve Christman 8/12/00; updated 2/9/04, 5/2/12