Tree of the Month: Kentucky Coffee Tree

The Kentucky coffee tree is one of the more distinctive trees found in Nashville’s urban forest due to its large seed pods and characteristic form. In this article, we’ll go over what it is about the Kentucky coffee tree that makes it such an effective member of the local canopy.

Is the Kentucky Coffee Tree From Kentucky?

The Kentucky coffee tree (Gymnocladus dioicus) is native to the eastern Midwest (across the states of Missouri, Illinois, and Indiana), and its natural range reaches into both Kentucky and Tennessee. As the American frontier moved westward, the tree was first encountered in Kentucky, and the area was marketed to settlers by suggesting that the tree’s bean could be used as an alternative to coffee. The caffeine-free drink wasn’t necessarily a substitute, but the common name held on from this association.

What Does the Kentucky Coffee Tree Look Like?

A medium-sized canopy tree, a Kentucky coffee tree grows up to 75 feet at a rate of about one to two feet per year until it reaches its mature height when its growth gradually slows. The tree has wide, meandering branches and an open, airy canopy. The first part of the tree’s scientific name, Gymnocladus, refers to the tree’s “naked branches.” The inner branches of the tree are bare, allowing some light through its crown and resulting in a speckled shade (which makes it a good partner for understory trees) while offering an interesting appearance.

The bare inner branches are a result of the way the Kentucky coffee tree leaves grow on these trees. What appear as small branches with 20 to 30 leaves are actually a single compound leaf with many leaflets. The Kentucky coffee tree’s leaf is one of the largest of all American trees—these bunches of leaflets grow along a twig-like structure that grows to three or four feet long. The leaflets have smooth edges and a pointed oval shape. 

The second part of the scientific name, dioicus, refers to the fact that there are both male and female specimens of this species. The female coffee tree produces the tree’s namesake woody bean pods (it’s a member of the legume family, after all), while male specimens don’t. This is something to keep in mind when planting a Kentucky coffee tree, since the bean pods can create a bit of a mess along walkways and streets when they drop off the tree in fall. 

In the late spring, Kentucky coffee trees have small white to green flowers in bunches that attract pollinators like bees, moths, and butterflies. Once pollinated, the tree grows flat, greenish-yellow pods that are up to eight inches in length, which dry out over the summer. While the peeling gray bark of the Kentucky coffee tree is attractive to some insects as habitat (including caterpillars that become pollinators) and the wide branches attract squirrels and birds, most animals otherwise avoid the tree since the pods don’t offer a food source due to their raw toxicity. 

Kentucky Coffee Trees in the Nashville Landscape

In nature, Kentucky coffee trees can be found in dry fields, on wooded slopes, in bottomlands, and along waterways, giving them a robust versatility in various types of soil and tolerance to drought and flooding. As the tree ages, it helps manage the environment as well, stabilizing soil, filtering air, and managing groundwater, among other ecosystem services. This species prefers full sunlight and can stand some pollution, making it as remarkable a tree species for urban streets as it is for residential yards. 

Try the Kentucky Coffee Tree for Yourself!

Check out the listing for the Kentucky coffee tree through the Nashville Tree Conservation Corps’ tree sale, which makes a range of robust species available to Nashvillians at below-retail prices (with delivery included). If you don’t have a place to plant a tree, consider volunteering with us or donating a tree for us to plant! We welcome financial donations, which are an important source of funding for our mission. Subscribe to our email newsletter to stay on top of NTCC’s activities and tree care tips, and check out our Linktree for more ways to get in touch.