A Crimson King Norway Maple (acer platanoides) is a distinctive looking deciduous tree with dark, plum-colored leaves, that grows to about 45-feet (13.7m) in height with a 25 to 40-foot (7.6-12m) spread when mature. It is a moderate grower that produces a dense, shady crown, oval in shape, and adapts to most types of soil and a wide variety of conditions. Non-native to the United States, it was introduced to Philadelphia in 1792 for use as an ornamental tree. It is generally suited to geographical zones four through seven, but is also grown outside these zones in places like California.
The burgundy leaves of the Crimson King Maple are star-shaped, with the leaf margins lobed, dentated and incised. In springtime, the tree sprouts maroon-yellow blossoms and the dark leaves persist spring through fall, before turning deep brown, bronze or yellow, and shedding. Dual-winged seeds also drop in the fall, propagating easily thanks to the hardy, adaptable nature of the species. Except to shape when young, these trees require little pruning.
The dark purplish leaves of the Crimson King Maple makes it a stand-out specimen, often used in landscaping to provide a visually stunning accent. In the northeast the tree is quite common, and uses include parks, tree-lined medians, sidewalk cutouts and parking lot islands. Due to easy propagation, the tree is considered aggressive and invasive.
At home the Crimson King Maple makes a handsome shade tree with a few caveats. The root system is shallow and some roots might bulge from the ground, interfering with mowing. The tree will also pull water and nutrients from the topsoil that surrounds the root system, competing with grass, making it more difficult to grow lawn directly beneath it, particularly in drier regions. The shallow root system can also be destructive, and trees should be planted a minimum of five feet (1.5m) from a sidewalk, patio, or structure. If the site is intended to eventually accommodate a mature tree, consider potential problems such as overhead power lines.
Many people mistakenly refer to a Crimson King Maple as a Red Maple. There are several species of maples whose leaves are green until fall when they turn bright red, scarlet or gold before shedding. Other maples have green leaves with red stems and veins. The leaves of the Crimson King Maple, however, are so dark that they appear closer to black, only changing color in fall.
Tolerant of urban pollution and bouts of drought, the Crimson King Maple is quite hardy and can be successfully transplanted. The best time to plant this tree is early-to-mid spring. Specimens are available through online outlets and might also be ordered from or stocked at local nurseries. The more mature the tree, the higher its price, but generally the tree is quite affordable.