The red maple (Acer rubrum) is one of the most common, and popular, deciduous trees in much of the eastern and central U.S. It has a pleasing oval shape and is a fast grower with stronger wood than most of the so-called soft maples. Some cultivars reach heights of 75 feet, but most are a very manageable 35 to 45 ft. tall shade tree that works well in most situations. Unless irrigated or on a wet site, a red maple is best used north of USDA hardiness zone 9; the species is often much shorter in the southern part of its range, unless it is growing next to a stream or on a wet site.
Arborists recommend this tree over the silver maple and other soft maple species when a fast growing maple is needed because it is a relatively tidy, well-shaped tree with a root system that stays within its boundaries and limbs that do not have the brittleness of other soft maples. When planting the species Acer rubrum, make sure it has been grown from local seed sources, as these cultivars will be adapted to local conditions.
The outstanding ornamental characteristic of the red maple is its red, orange or yellow fall color (sometimes on the same tree) lasting several weeks. Red maple is often one of the first trees to color up in autumn, and it puts on one of the most brilliant displays of any tree. Still, trees vary greatly in fall color and intensity. Species cultivars are more uniformly colored than the native species.
The newly emerging leaves and red flowers and fruits signal that spring has come. They appear in December and January in Florida, later in the northern part of its range. The seeds of red maple are quite popular with squirrels and birds. This tree is sometimes confused with red-leaved cultivars of Norway Maple.
Tips for Planting and Maintaining
The tree grows best in wet locations and has no other particular soil preference, although it may grow less vigorously in alkaline soils, where chlorosis may also develop. It is well-suited as a street tree in northern and mid-south climates in residential and other suburban areas, but the bark is thin and easily damaged by mowers. Irrigation is often needed to support street tree plantings in well-drained soil in the south. Roots can raise sidewalks in the same manner as silver maple, but because the red maple has a less aggressive root system, it makes a good street tree. Surface roots beneath the canopy can make mowing difficult.
Red Maple is easily transplanted and is quick to develop surface roots in soils ranging from well-drained sand to clay. It is not especially drought tolerant, particularly in the southern part of the range, but selected individual trees can be found growing on dry sites. This trait shows the wide range of genetic diversity in the species. Branches often grow upright through the crown, forming poor attachments to the trunk. These should be removed in the nursery or after planting in the landscape to help prevent branch failure in older trees during storms. Selectively prune trees to retain branches that have a wide angle from the trunk, and eliminate branches that threaten to grow larger than half the diameter of the trunk.
In the northern and southern end of the range, make sure to consult with local experts to choose cultivars of red maple that are well adapted to your region. Some of the most popular cultivars are as follows:
- 'Armstrong': A 50-ft. tall tree with an upright growth habit, almost columnar in shape. Its canopy is 15 to 25 ft. wide. It is somewhat prone to splitting branches due to tight crotches. Glossy leaves turn a bright shade of red in fall. Appropriate for zones 4 through 9.
- 'Autumn Flame': A 45-ft. tall cultivar with a round shape and above-average fall color. Canopy is 25 to 40 ft. wide. Appropriate for zones 4 through 8.
- 'Bowhall': Roughly 35 ft. tall when mature, this cultivar has upright growth habit with a canopy 15 to 25 ft. wide. It grows best in acidic soil and is appropriate in zones 4 through 8. This is a cultivar that works well as a bonsai specimen.
- 'Gerling': About 35 ft. tall when mature, this densely branched tree has a broad pyramidal shape. Canopy is 25 to 35 ft. wide. Appropriate for zones 4 through 8.
- 'October Glory': This cultivar grows 40 to 50 ft. tall with a canopy that is 24to 35 ft. wide. It has above-average fall color and grows well in zones 4 through 8. This is another cultivar that can be used as a bonsai.
- 'Red Sunset': This 50-ft.-tall tree is a good choice in the South. It has a brilliant red color, with a canopy 25 to 35 ft. wide. This tree can be grown zones 3 through 9.
- 'Scanlon': This is a variation of Bowhall, growing 40 to 50 ft. in height with a canopy 15 to 25 ft. across. Turns bright orange or red in fall, and grows well in zones 3 through 9.
- 'Schlesinger': A very large cultivar, rapidly growing to 70 ft. with a spread as much as 60 ft. Beautiful red to purple-red fall foliage that holds its color for as much as a month. It grows in zones 3 through 9.
- 'Tilford': A globe-shaped cultivar that grows up to 40 ft. in height and width. Varieties are available for zones 3 through 9. The variety of drummondii is ideal for zone 8.
Scientific name: Acer rubrum (pronounced AY-ser Roo-brum).
Common name(s): Red Maple, Swamp Maple.
USDA hardiness zones: 4 through 9.
Origin: Native to North America.
Uses: An ornamental tree usually planted lawns for its shade and colorful fall foliage; recommended for buffer strips around parking lots or for median strip plantings in the highway; residential street tree; sometimes used as bonsai species.
Height: 35 to 75 feet.
Spread: 15 to 40 feet.
Crown uniformity: Irregular outline or silhouette.
Crown shape: Varied from round to upright.
Crown density: Moderate.
Growth rate: Fast.
Leaf arrangement: Opposite/subopposite.
Leaf type: Simple.
Leaf margin: Lobed; incised; serrate.
Leaf shape: Ovate.
Leaf venation: Palmate.
Leaf type and persistence: Deciduous.
Leaf blade length: 2 to 4 inches.
Leaf color: Green.
Fall color: orange; red; yellow.
Fall characteristic: showy.
Light requirement: Part shade to full sun.
Soil tolerances: Clay; loam; sand; acidic.
Drought tolerance: Moderate.
Aerosol salt tolerance: Low.
Soil salt tolerance: Poor.
Most red maples, if in good health and free to grow, need very little pruning, other than training to select a leading shoot that establishes the tree's framework.
Maples should not be pruned in spring when they will bleed profusely. Wait to prune until late summer to early autumn and only on young trees. Red maple is a large grower and needs at least 10 to 15 feet of clear trunk below the bottom branches when mature.