Aspen is fast-growing hardwood. Its shimmering leaves flutter throughout the summer before turning gold in the fall. Aspens grow in most of the United States, but thrive in the arid West. Aspens are the most widely distributed tree in North America. They are used for pulpwood and construction materials.
Aspen trees grow to 50 feet with a 25 foot spread in USDA Hardiness zones 1 to 7. Their bark is smooth, light gray or off white, sometimes with an olive cast. The bark on the narrow trunk has shallow furrows that look like horizontal lines. The yellow-green leaves are semi-rounded, coming to a point and up to 3 inches wide. Quaking aspen leaves have very tiny teeth; bigtooth aspen leaves have large, jagged teeth.
Life Span and Problems
Aspens are short-lived trees, often surviving only 30 to 50 years. Many diseases and pests can further shorten their lives. Aspens are susceptible to diseases such as cytospora cankers, leaf spots and rust. Oystershell scale, aphids and aspen twiggall fly are prevalent on urban trees. Other pests include gypsy moth, poplar borer and forest tent caterpillar.
This fast-growing tree ranges from the northeast coastal states to Alaska, down the Rocky Mountains and into central Mexico. According to the Colorado State Extension, aspens serve as a "succession" tree. They will quickly regrow and reseed when other vegetation is lost to disease, logging, erosion, fire or insects. Some homeowners consider aspen trees to be a nuisance because of their suckering. Suckers will shoot off from the roots of the mother tree and can quickly take over a yard.
Aspen trees prefer moist, well-drained, slightly acidic soil. They grow best on the north and east side of buildings. According to San Francisco State University, aspens prefer "cool, relatively dry summers with lots of sun, and winters with abundant snow ... that recharges soil for growth during spring and early summer."