Easily identified by their thin, papery bark in white, yellow, or gray, birch trees are frequently found in colder climates of the Northern hemisphere. With a shallow root system, they prefer moist soil and afternoon shade. They have a tendency to colonize open areas and offer stunning color displays when foliage turns in the fall.
With a rich history and large, stately shape, cottonwood trees are a fast-growing native of the United States. Growing 6 feet a year in zones 2 through 9, they reach over 100 feet tall and almost as wide. Female trees disperse a white cottony covering from their seeds as they ripen in the summer, giving the tree its common name.