Poplar trees grow all across the United States. These trees are large, with some varieties reaching heights of 100 feet or more. The trunks may be 3 to 4 feet in diameter. Many varieties are also fast growing. Some poplar varieties prefer to grow in floodplains and valleys near streams.
Poplar bark varies in color and texture. The Eastern poplar, also known as the cottonwood, has bark that begins greenish-yellow and turns gray. This bark becomes furrowed with age. The white poplar has light bark with black, diamond-shaped scars. The balm of Gilead poplar (Populus gileadensis) has gray smooth bark. The bigtooth Aspen also has smooth bark, but it is greenish.
Some poplars, like the Carolina poplar (Populus canadensis), the Eastern poplar (Populus deltoides) or Cottonwood, have rounded triangular-shaped leaves. Other poplar leaves are lobed, such as those of the white poplar (Populus alba). Finally, the leaves of the bigtooth Aspen (Poplar) or the swamp poplar (Populus heterophylla) are wide at the bottom with a pointed tip.
Poplars bear male and female flowers on separate trees. The flowers bloom in catkins. Most often, the catkins appear before the leaves. Some species, like the swamp poplar or Eastern poplar, both of which are known as the cottonwood, produce a cotton-like hairy substance with the seeds. This cotton makes this tree undesirable for landscape planting.
A large root system supports the large poplar tree. For this reason, poplars are not often planted as ornamental landscape trees. The roots invade sewer drains. In addition to invading drains, poplar roots send up suckers. These suckers grow quickly into trees and can damage sidewalks and foundations.