Aspen trees are part of the Willow family and one, the quaking aspen, is North America's most widely distributed tree in terms of its range. Aspens make interesting landscape trees since they are attractive and their leaves flutter in the wind, creating both a visual and an audio effect. Aspen trees have many things in their favor, but they also have some drawbacks.
The bigtooth aspen is a species located mostly in the Northeast and around the Great Lakes. The quaking aspen's range spans the entire continent. It grows from Alaska eastward through most of Canada and across much of the northern United States and into the Rockies as far south as New Mexico. Aspens grow best when planted in full sun and require moist soil to develop.
The leaves of a quaking aspen are almost round and can be as long as 3 inches. They are shiny green on the upper surface and a duller green underneath. Bigtooth aspen has larger leaves with more distinct "teeth" along the edges. Both types have flattened stems that are long and slender, which contributes to the leaves' habit of swaying back and forth in even light winds.
Quaking aspens are between 40 and 50 feet tall and as wide as 30 feet when they mature, with their crown having a rounded appearance. Bigtooth aspens have a similar height and both species have the capability to grow as much as five feet in a single year as they mature.
The yellow fall color of an aspen tree is one of its assets as a landscape species, along with its bark, which is greenish-white to creamy white on the quaking aspen and dark green on a bigtooth aspen. The bigtooth aspen is relatively easy to transplant and makes a fine shade tree, while quaking aspen grows in many kinds of soil. The fact that aspens grow so quickly makes them a good landscape tree. Aspens will be mature in a shorter time than most other species.
The roots of these trees spread out, so avoid putting them near sewers, sidewalks or septic systems that they could potentially infiltrate. Quaking aspen does better in numbers, with lone specimens prone to disease and the effects of the weather. Aspens do not live long, according to the Colorado State University Cooperative Extension website, with many unable to see their 20th birthday. Diseases like rust, leaf spot, cankers and fungal ailments can shorten the life of an aspen. Insect pests like aphids and scales also take their toll on aspen trees.