It is considered a pioneer species it is often a primary invader of sites which have been cleared or burned. It seldom exceeds 60 feet in height and 20 inches in diameter. Quaking or trembling aspen is a short lived (50 years), fast growing, medium sized tree. Twigs are slender, orange to dark brown, with half-round leaf scars with three bundle scars. The bark on young trees is thin, pale-green to creamy white on older trees it becomes thick, roughened by warty bands, divided into flattened ridges and almost black in color. The bud is shiny dark brown in color and slightly sticky. Winter buds are 1/4 to 1/2 inch long, closely appressed to the twig, each with its lowest bud scale directly lined up with the leaf scar. The leaf is broadest near the base, has a short pointed tip and is finely toothed along the margin. Quaking Aspen Twig - Photo by Paul Wray, Iowa State UniversityĪspen leaves are simple, alternate, nearly round in outline, 2 to 3 inches in diameter with a flattened petiole 2 to 3 inches long. Seed Stratification: No stratification period is needed. Seed Bearing Frequency: Every 4 to 5 years Leaves: Alternate, simple, single toothed, and triangle shaped Site Requirements: Native to North America, aspen trees grow naturally in moist sites and full sun. Height: Mature size varies with species, ranging from 50 feet to 100 feet. Quaking Aspen Leaves - Photo by Paul Wray, Iowa State University Most often found in the northern half of the state.

Habitat: Grows in open woods and moist prairies or woodland edges. Because of intensive competition from other species in Iowa, it is most common on dry, upland soils. In Iowa, quaking aspen is very common in eastern Iowa and found locally in southern and western Iowa along the major river valleys. The best growth occurs on soils which are rich and porous, often where lime or limestone is present.

It thrives on a wide variety of sites, from shallow rocky or clay soils to rich, sandy soils. In grows from northern Alaska to Labrador and south into Mexico. Of all the native trees in North America, quaking aspen ( Populus tremuloides) has the greatest distribution.

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