Aspen Varieties

Quaking Aspen

• The quaking aspen occurs naturally from Alaska across nearly all of Canada, with its range extending into the northeastern quarter of the United States and throughout the Rocky Mountains. Growing to 50 feet high, quaking aspen handles the cold as far north as U.S. Department of Agriculture plant hardiness zone 1. Named for its leaves, which have flattened stems and a large surface area that makes them rustle in any breeze, quaking aspen develops new growth from its roots. Entire colonies of the tree in the wild are often the result of a single tree, with its clones springing up about it.

Bigtooth Aspen

• The dark green foliage of the bigtooth aspen, Populus grandidentata, has several obvious, coarse teeth along its edges, which helps distinguish this tree from quaking aspen. Limited to the northeast, from the Great Lakes to New England and southeastern Canada, it has a much smaller range than quaking aspen. Bigtooth aspen grows to 70 feet, doing best in full sun and damp areas. It works well as a lawn tree or shade tree, but it should be placed well away from structures such as sidewalks and sewers, or its root system can infiltrate them and cause damage.

European Aspen

• European aspen, Populus tremula, withstands the climate of Siberia, so it is a fit for northern states and Canadian provinces. European aspen grows to 70 feet and it bears a close resemblance to quaking aspen. Its darker trunk, larger flowers and serrated foliage help distinguish it from its close cousin. European aspen's foliage has a coppery-brown hue when it first emerges, but the leaves turn a grayish-green as the growing season wears on.

Aspen Facts

• Aspen foliage has ornamental value in autumn, when it turns shades of yellow. All the aspens are vulnerable to a host of insect pests and tree diseases. Bugs such as scales, borers and aphids afflict these trees, and ailments such as powdery mildew and leaf spot affect the quality of the foliage. Aspens will lose their leaves prematurely during a hot summer; these trees do not tolerate humid and hot climates, with USDA zone 6 the warmest zone they will thrive in.