PSC 2620: Woody Trees and ShrubCourse HomeWeek 11

Populus tremuloides - Quaking Aspen

Plant Viewer
The leaf of the Quaking Apsen is 1 1/2 - 3 inches long and ovate in shape with a undulately serrated margin. They leaves are a lighter color on the back, and when they twist back and forth in the wind they create the famous quaking appearance. The bark is gray-white and smooth.
Aspen spread by means of underground roots to start new clones. Through this method they can form large colonies of trees. In fall, the foliage of Populus tremuloides turns a brilliant yellow color.

Plant Description

Populus tremuloides, or Quaking Aspen, is a medium to large sized tree with an upright growth habit. It is native to the higher altitudes of the region, growing on the mountainsides in large colonies. It can grow 40-50 feet high and 20-30 feet wide. It prefers moister conditions in a sunny location, but is fairly adaptable to drier locations. The bark is a gray-white color that can approach the white color of Betula pendula as the tree ages. Fully mature trees will have furrowed and darker brown bark.

The leaves are 1 1/2 - 3 inches long and wide, being ovate in shape, tapering to a point and having an undulately serrated margin. The leaf is arranged alternately on the stem. It is a dark green color on the top of the leaf and a light green color on the bottom. When the wind blows it creates a quaking effect in the tree, causing the leaves to rotate on their petioles, which creates a shimmering effect as the leaf alternates between the dark and pale sides being visible. In the fall the foliage turns a deep and rich yellow color.

Landscape Use

Plant the tree in clumps, or plan on it forming into clumps. It is a very popular tree in high altitude landscapes where it is one of the few trees that will truly thrive. It can be used as an ornamental or shade tree.

Points of Interest

Quaking Aspen spreads rapidly and continually by sending up suckers. By doing this, a massive grouping of trees can be connected to the same root system.

It is very susceptible to borers, and the trees should be constantly monitored for any sign of damage. It is best to keep the tree healthy to avoid a potential infection.

Notable Cultivars

Populus tremula - Erecta
This very narrow tree grows 40 feet tall but only 8-12 feet wide. The margin of the leaf is noticeably more undulate than Quaking Aspen, and the fall color is a mixture of oranges and yellows.