Birch trees and aspen trees have a similar appearance, but possess significant differences, specifically in their leaves, buds, bark and abilities to tolerate extreme climates. Additionally, while aspen trees are found across the country, birch trees are primarily found only in the eastern United States and areas of Canada, according to Garden Guides.
The most visible difference between the trees is the bark. Aspen trees have smooth, white bark while birch bark can be gray, grayish-white, red or black. Additionally, horizontal markings mar the surface of birch trees while aspens typically only show knots or scars, as noted by Garden Guides.
Another stark difference between the trees is in the leaves. Birch trees have leaves that are rough along both sides. Aspen tree leaves are rounded with smooth bumps along the edges. Both turn bright colors during the fall months.
Birch trees form buds in the spring and blossom fully by mid-to-late summer, while aspen trees bud and blossom later, reaching full bloom later in the year.
Finally, while the aspen tree grows well in the more moderate temperatures and requires full sunlight, the birch tree grows well in partial shade and is able to withstand harsher climates with significantly less difficulty.