Trees of Dickinson County: Cottonwood

If you walk around the Iowa Great Lakes, you’ll see plenty of towering cottonwood trees (Populus deltoides).

They live to be 80-100 years old, although they have weak branches that struggle to withstand ice and rain.

The heartwood of the trunk tends to rot inside a cottonwood, and sometimes when branches break off, that allows small mammals access to the hollow interior, which serves as a safe home.


Cottonwood trees can grow 75 to more than 100 feet tall, and they have very wide canopies. Trunks are also quite wide, up to 4 feet in diameter.


Cottonwoods are common in the Iowa Great Lakes area because they like wet mesic soil. You can find them in river floodplains or near wetlands.


Cottonwoods can easily be identified by their leaves. Leaves are shaped like a rounded triangle, are simple and are located alternately along the branch. Each leaf is 3-6 inches, smooth and has a toothed edge.


These trees get their name from the seeds that they produce. They grow in a capsule with long lines of seeds that then float in the breeze on a cotton-like tuft.

cottonwood seeds