7. Norway Maple

Acer platanoides: Norway Maple (Crimson King)

Cultural Significance

Glancing from any hilltop in the Hudson Valley, you will notice a bright-red star amongst a sea of green. The red you notice may be the leaves of the Crimson King, a variety of the Norway maple (Acer platanoides).

The tree is popular in its native Europe and plays a part in Norwegian culture. It was first made available in the United States in 1759 by a Pennsylvania horticulturalist. In 1792, George Washington ordered two Norway maples for his garden at Mount Vernon. Since then, it has been one of the most popularly planted trees, mostly for landscaping purposes. Because of its early introduction, rapid growth and means of dispersal, Norway maple is fully integrated into North American forests, with little likelihood of removal. Crimson King is a beautiful tree, but requires discretion when planting because of its invasive characteristics.

Native Ecosystems

The Norway maple is found throughout all of Europe, and even stretches into Asia. It is found at high and low elevations, growing best in river valleys and in the foothills of mountains. It needs nitrogen-rich soil with a pH above four. It thrives in moist soils that allow the tree to stretch its roots laterally and fairly deep into the ground.

The Norway maple is considered by most to be a highly invasive species in the United States and some states are now warning against its planting. Its invasiveness is due to its extreme shade tolerance (especially in youth) and its tendency to crowd-out and replace other species. Once established, Norway maple monopolizes sunlight and may even secrete chemicals that prevent other species from growing. Even when the tree is cut, it may re-sprout, and grow another trunk.

Bred for its foliage and shade, Crimson King is a deciduous tree found throughout continental Europe and Scandinavia. Since its introduction to the continental United States in the 18th century, the varieties of Norway maple continue to be amongst the most popularly planted trees in North America. Norway maples are known for their robustness, shade-tolerance, rapid growth and their ability to quickly modify their environment. It is only recently that Norway maples have gained a negative reputation.

Beneficial Uses

The wood is generally classified as “hard,” making it useful for some aspects of woodworking. A chemical compound known as anthocyanins, which have strong herbal and pharmaceutical properties, causes the redness of the leaves.

Biological Characteristics

The Norway maple has a typical lifespan of 150 years. It can grow to a maximum height of 60 feet and reach a diameter of 76 inches at eye level. The bark of a mature tree can be brown to grey, with folding or ridges developing over time. Norway maple’s wood is often compared to its native relative, the Sugar maple (Acer sacharum). The Crimson King has the distinct maple leaf, which are five lobed. The size of an individual leaf can range from 4-7” in length, with a width to match.

Norway maples are dioecious, with male and female trees. They are insect pollinated and the red leaves tend to attract good insects, or those that do not parasitize the tree. The winged fruits (samaras) are distributed by the wind. They are commonly known as “helicopter seeds,” as they spin to the ground after breaking from the tree.