June 27, 2013
Acer platanoides select cultivars such as
'Columnare', 'Crimson King', 'Globosum', 'Royal Red'

Norway Maple

DescriptionThe Norway Maple is a medium sized shade tree that can tolerate air pollution, drought and poor soils while providing dense shade and an aesthetically pleasing form to the streetscape. Planting applications must consider the impact of the viable seedlings that will be produced each year.
UsageStreet tree, parking lot island, shade tree; settings away from natural areas.
Hardiness zone4
Size5-17m, depending on cultivar.
Form/textureSymmetrical, dense, shape varies with cultivar.
Growth rateModerate to rapid.
LeafOpposite, simple, lobed.
Colour varies with cultivar, from all-season green, variegated, purple red in spring to all season dark green-red.
FlowerYellow to greenish yellow clusters, early spring, somewhat showy, appearing before leaves.
FruitSamara, abundant, viable.
Exposure/cultureFull sun to shade.
Tolerant of wide range of soils, including range of pH.
Tolerates occasional wet to very dry soils.
Easily transplanted.
Tolerates poor air quality.
Dense foliage casts dense shade.
CommentsLong planted as a street tree, this is often the homeowner's tree of choice. The red-leafed cultivars are often called the 'red maple', not to be confused with Acer rubrum, the native red maple.
Popularity seems to ignore the bark splitting, sidewalk heaving, girdling roots and foliar diseases. Norway maples do grow quickly, but their urban tolerance is producing generations of unwelcome seedlings that are growing in natural areas throughout the continent (www.invasiveplantatlas.org). These seedlings prove to be very shade tolerant and able to live in the understory for decades. There have been studies to determine which cultivars might have the fewest viable seeds (Conklin). There are many other suitable trees for the urban landscape that could be planted while the research determines which Norway maple cultivars might pose the least risk to our natural areas.

Conklin, J.R. and J.C. Sellmer. 2009. Flower and Seed Production of Norway Maple Cultivars. Hort Technology 19(1): 91-95.
Conklin, J.R. and J.C. Sellmer. 2009. Germination and Seed Viability of Norway Maple Cultivars, Hybrids and Species. Hort Technology 19(1): 120-126.