- Boxelder Tree Information – Learn About Boxelder Maple Trees
- Boxelder Tree Information
- Boxelder Maple Tree Growing
- The Friends of the Wild Flower Garden, Inc.
- The Ashleaf Maple – Box Elder
- Environmental Studies
- Female box elder tree
- Boxelder trees are toxic to horses
Boxelder Tree Information – Learn About Boxelder Maple Trees
What is a boxelder tree? Boxelder (Acer negundo) is a fast-growing maple tree native to this country. Although drought resistant, boxelder maple trees do not have a lot of ornamental appeal to homeowners. Read on for additional boxelder tree information.
Boxelder Tree Information
What is a boxelder tree? It’s an easy-to-grow, very adaptable maple. The wood of boxelder maple trees is soft and has no commercial value. Boxelder maple tree facts tell us that this maple usually grows on river banks or near water in the wild. These trees help to shelter wildlife and stabilize stream banks. However, in urban areas, they are considered a type of weed.
Some boxelder maple trees are male and some are female. The females bear blossoms that turn bright green when they are pollinated. They can add color to your spring garden. However, most experts do not recommend that gardeners begin boxelder maple tree growing. Nor are they very popular garden plants.
Boxelder maple tree facts tell us that these trees have brittle, weak wood. That means that the trees break easily in wind and ice storms. In addition, boxelder maple tree information confirms that the tree seeds, found in winged samaras, germinate very easily. This can make them a nuisance in a private garden.
Finally, female trees attract boxelder bugs. These are insects some ½ inch long that don’t cause many problems in the garden. However, boxelder bugs are problematic as winter comes on. They like to overwinter indoors, and you’ll likely find them inside your house.
Boxelder Maple Tree Growing
If you decide to plant one of these trees, you’ll need to get information about boxelder maple tree growing. Given the tree’s tolerance and adaptability, boxelder maple trees are not difficult to grow in the proper climate.
These trees can grow in almost any mild, cool or cold region in the United States. In fact, they thrive in U.S. Department of Agriculture plant hardiness zones 2 through 9.
Plant your boxelder near a stream or river, if possible. They tolerate most soils, including sand and clay, growing happily in dry or wet soil. However, they are sensitive to salt spray.
The Friends of the Wild Flower Garden, Inc.
Boxelder is a medium sized native deciduous tree, growing 30 to 60 feet high with a short trunk (frequently branched) and a broad open crown when growing unobstructed, but in close quarters it will be irregular and main branches will twist and turn to achieve light.
The bark is fairly thin, gray to light-brown with many narrow ridges and fissures that with age are more deeply furrowed and the ridges become interlacing.
Twigs are green, often with purplish tones and when very young, whitish, with white lenticels, mostly hairless, ringed at the leaf nodes from leaf scars that meet at a raised point. Terminal buds are light colored with hair, lateral buds are tight to the twig.
Leaves are opposite, stalked, pinnately compound with 3 to 5 leaflets (sometimes 7), up to 6 inches long, light green above, paler below. The individual lateral leaflets have short stalks. They are variable in shape, ovate to elliptical with sharp pointed tips, somewhat rounded at the base, and coarsely saw-toothed, sometimes with lobes. Leaf stalks are often reddish later in the season, but green early in the season. Leaves are yellow in fall with the red leaf stalks. Box elder is the only maple with divided leaves. See the leaf comparison at bottom of the page.
Flowers: The tree is dioecious, that is the male and female flowers are on separate trees. Male flowers (staminate) are yellow-green and appear in spring just before the leaves, or with the young leaves, on slender stalks from a common point, near the end of twigs. The calyx of the male flower is yellow-green with 5 very short sepals and no petals and 5 protruding stamens that have long anthers that are dark red initially. Each flower is on a long stalk. The female flowers (pistillate) are more reddish-green with the same 5 sepals and a pistil and a divided style and develop long hairy stalks. They hang in drooping racemes.
Seed: Female flowers mature to a one-seeded samara with a broad curved finely veined wing, 1 to 1-1/2 inches long that is paired with another, green initially and turning brown. The young samaras can vary in color with the local ecotype of the tree. The angle of joining of the pair is very acute. These mature in the fall and often persist on the tree into winter. They are wind dispersed. Trees require about 8 to 11 years to produce a quantity of seed.
Habitat: The tree grows from a vigorous shallow and spreading root system but is somewhat short-lived, but fast growing. In a native environment it is found in moist bottom-lands but can quickly colonize disturbed sites. Seedlings need sun for the tree to continue to grow, which can result in twisted shapes on trees that found a light source. Damage to the trunk will result in new sprouts and the tree re-sprouts from cut stumps. The nymph of the common boxelder bug feeds on the female flowers and young seeds but does not seem to greatly damage the tree.
Names: The genus, Acer, is the Latin word for ‘maple’. The species name, negundo, is an old reference to an Asian species, Vitex negundo, that resembles this species. The alternate common name of Ash-leaved Maple refers to the leaves resembling the ash tree compound leaves. In older literature the tree was classified as Negundo fraxinifolium. The author name for the plant classification, ‘L.’ is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. Botanists have recently move the maples into the Sapindaceae family from the older Aceraceae family.
Box Elder (Acer negundo) is a species of maple native to North America. Box elder, boxelder maple, and maple ash are its most common names in the United States. It is used mainly for ornamental and decorative purposes, with lumber exhibiting reddish pink heartwood streaks being the most commonly seen. Dyed/stabilized burl blocks for use in turning projects are also available. Common uses for Box Elder include: turned objects, small ornamental objects, wood pulp, charcoal, boxes, and crates.
Box Elder (Acer negundo) was identified in 1959 as the material used in the oldest extant flutes from the Americas that were made of wood. These early artifacts, excavated by Earl H. Morris in 1931 in the Prayer Rock district of present-day Northeastern Arizona, have been dated to 620-670 CE.
The style of these flutes, now known as Anasazi flutes, uses an open tube and a splitting edge at one end. This design pre-dates the earliest known Native American Flute (which use a two-chambered design) by approximately 1,200 years. For years, researchers and Mycologists have attempted in vain to understand the etiology behind the brilliant red pigmentation found in some Boxelder trees. Woodturners delight in finding such a prize. Sometimes called “Ash-leaved Maple” because of it’s non-typical leaves, Box Elder is technically considered a maple tree.
The Ashleaf Maple – Box Elder
Ashleaf Maples (Acer negundo) are also known as Box Elders although this name does a poor job of giving reference to the taxonomic relationships of the species. You see, it’s not an elder. Instead, like other maples, they are in the family Sapindaceae.
Other names for the tree include include Ash Maple, Ash-leaf Maple, Black Ash, California Boxelder, Cutleaf Maple, Cut-leaved Maple, Negundo Maple, Red River maple, Stinking Ash, Sugar Ash, Three-leaved Maple and Western Boxelder.
The Poison-Ivy Look-alike
Ashleaf Maples are sometimes misidentified by amateur outdoor enthusiasts as poison ivy. The leaf of the tree often has 3 leaflets that resemble those of poison ivy. Ashleaf Maple is in no way dangerous though and it is easily distinguished with a closer look at the plant.
Tree Size: Small short-lived tree that grows from 10 to 2 m tall. The trunk has as diameter of 30 to 50 cm.
Branch color: Branches are green in color. Sometimes the bark on the trunk is pale gray or light brown. Shots are green with a whitish to pink or violet waxy coating when young.
Leaves: Leaves are pinnately compound and usually have from 3 to 5 leaflets. Sometimes there are seven present but this is rare. The leaflets are 5-10 cm long and half as wide. They have serrate margins
(edges). The color is light green and they turn yellow in the fall.
Flowers: The flowers are small and appear in the early spring. Seeds are slender, 1-2 cm long and have incurved wings. They drop on the fall. The plant is dioecious meaning that there are male trees and female trees.
Box elder, also commonly known as ashleaf maple, Manitoba maple, box-elder maple, and western box-elder, is a small-to-medium-sized tree, reaching heights of 50 to 75 feet, with a trunk diameter up to 4 feet. The trunk is relatively short and tapering, and the crown is spreading and bushy.
Leaf: Opposite, pinnately compound, 3 to 5 leaflets (sometimes 7), 2 to 4 inches long, margin coarsely serrate or somewhat lobed, shape variable but leaflets often resemble a classic maple leaf, light green above and paler below.
Flower: Species is dioecious; yellow-green, in drooping racemes; appearing in spring.
Fruit: Paired V-shaped samaras, 1 to 1 1/2 inches long, in drooping clusters, light tan when ripe in fall, persist throughout winter.
Twig: Green to purplish green, moderately stout, leaf scars narrow, meeting in raised points, often covered with a glaucous bloom; buds white and hairy, lateral buds appressed.
Bark: Thin, gray to light brown, with shallow interlacing ridges; young bark is generally warty.
Form: Medium sized tree to 60 feet, typically with poor form and multiple trunks; sprouts often occur on bole.
- pinnately compound leaves resemble those of Fraxinus, but leaflets are irregularly shaped.
- green twigs with reddish brown upper surface have waxy bloom that can be rubbed off.
- broken twig has a strong, acrid smell.
- buds covered with silky white hairs.
- white, solid pith in twigs.
Box-elder has the broadest range of the North American Maples. It is present in every county in Illinois, reaching optimal growth along streams in floodplains where it occurs with other bottomland hardwoods. It extends from Canada to Guatemala (in the mountains), and from New York in the east to Florida, west to southern Texas, northwest across the great plains into Canada. Further west in Colorado and California it occurs on slopes, in valleys, and associated waterways.
Importance to Ecosystem
Boxelder communities provide important habitat for many
wildlife species and protect livestock from temperature extremes in
summer and winter. Many species of birds and squirrels feed on the
seeds of Boxelder. Mule deer and white-tailed deer use it in
the fall as a browse species of secondary importance.
In addition, this tree provides valuable cover for wildlife and livestock, especially in the Great Plains region where quality cover is often lacking. The degree to which this species provides environmental protection during one or more seasons for wildlife species.
Relationship to other Species
Humans: Box-elder wood is light-weight, soft, and not strong. It is used for low quality furniture, paper pulp, interior finishing, and barrel making. Syrup can be made from the sap.
Animals: The seeds are a source of food for birds and mammals, and are important because they stay on the tree through winter, when other food resources are scarce.
The boxelder bug (Leptocoris trivittatus), also called red shouldered bugs, feed on the leaves and seedpods of boxelder trees. Adult boxelder bugs are 1/2 inch long and have distinct red coloration on their wings. Boxelder bugs are not a serious pest of boxelder trees, but they reproduce rapidly on boxelder trees and are a nuisance pest when they make their way into homes. Adult bugs emit a foul odor and stain furniture indoors.
Boxedler aphids (Periphyllus negundinis) uses its long, penetrating mouth parts to feed on the vascular tissue of boxelder trees. In large numbers, boxelder aphids can stunt the growth of young trees. Boxelder aphids also secrete a sugar-rich honeydew while feeding that often leads to secondary fungal problems, according to Colorado State University.
Other interesting facts
- Box-elder and its seedlings grow on a variety of soils. Although it grows best on moist soils, box-elder is drought and cold resistant.
- It can also tolerate flooding for extended periods (up to a month). In bottomlands, it usually has a shallow root system that extends outward. This is an adaptation to unstable soils and the typically low oxygen content of flooded soils.
- Because of its thin bark, box-elder is susceptible to fire, ice, and wind damage.
- Box-elder is a relatively short-lived tree, typically reaching 60 (rarely 100) years of age. It is fast growing when it is young (the first 15 – 20 years).
Page Drafted By: Julia Giza
- Despite their reputation as “trash trees,” several ornamental cultivars are commercially available.
- Trees are hardy in U.S. Department of Agriculture hardiness zones 2 through 9.
- Grows on moist bottomland sites which are seldom subject to
- Flowers from March through May with or before the appearance of
- Throughout its range, Boxelder is most often associated
with various species of cottonwood (Populus spp.) and willow (Salix spp.).
Female box elder tree
This past October, box elder insects fed off the female box elder tree located less than five feet from our house. The tree seemed to produce a bumper crop of seed pods this year, and the insects were overwhelming, both for us and our neighbor. The bugs numbered in the thousands and came in through our sliding glass window and skylights. Even now, when the weather is mild, the bugs still congregate on the exterior of the house. We used insecticidal soap but were infested with the bugs for weeks. A similar scenario next year would be intolerable, and we note that the extension service recommends the removal of such trees if they grow near the house. Given the size and location of the tree, the price to remove it is high: $2,500 is the estimate we’ve received. Before we go ahead with the tree removal, we wanted to check with you again to see if there is any other effective alternative. We don’t see caulking and sealing as feasible to prevent the entry of the bugs, given their overwhelming presence. We’ve lived here 19 years and have seen the insects before but never in this volume. Is this year’s experience aberrational, or could we see a big infestation again next year? If the tree is not removed, is it possible that the tree pod seeds will spread through our community? Thanks for your response.
Boxelder trees are toxic to horses
Seasonal Pasture Myopathy (SPM) is an equine muscle disease which can be fatal in 90 percent of cases. The fall season appears to be when horses are at the highest risk of being affected by SPM with fewer horses affected in the spring and summer. Seeds of the boxelder tree, a maple species (Acer negundo) containing the toxin hypoglycin A, have been associated with Seasonal Pasture Myopathy in horses. Ingestion of sufficient quantities of boxelder seeds containing this toxin blocks fat metabolism and breaks down respiratory and postural muscle cells.
It’s important to understand that horses do not naturally eat boxelder tree seeds. In fact, some horses may live in a pasture where boxelder trees exist without ever being affected by SPM. However, there are some important risk factors to consider when deciding what to do with pastures containing boxelder trees, especially in the fall.
Photo credit: Tom Guthrie, MSU
Michigan State University Extension recommends the following considerations to minimize the risk of your horse being affected by SPM:
- Identify if there are any boxelder trees in or around your horse pasture. Boxelders have separate male and female trees, and the seeds are only found on the female trees.
- Do not expose horses to pastures in the fall with boxelder trees if:
- Horses are young or new to the pasture.
- Pasture is overgrazed.
- Horses are turned out on pasture for more than 12 hours per day.
- Horses on pasture are not provided with supplemental hay.
- Cut down the tree. By cutting down a female boxelder tree in a respective pasture may eliminate the immediate risk, it will not necessarily remove all risks because wind may blow boxelder seeds a long distance from trees located outside the pasture.
- Ensure your horse is fed before being turned out on fall pastures and has access to hay while on fall pastures.
- Reduce turn-out time or avoid using the pasture if risks are present.
SPM can be easily confused with colic or founder. Signs include reluctance to move, stiffness, difficulty walking or standing, reddish brown colored urine, rapid to difficulty breathing, increased periods of lying down with difficulty getting up.
If you suspect your horse may be affected by SPM, promptly contact your veterinarian. Blood tests that detect muscle damage and hypoglycin A toxin levels can help determine if your horse has SPM. If confirmed, aggressive medical treatment may be warranted.