Scientific Name
Gymnocladus dioicus
The Kentucky coffeetree is native to the U.S. Midwest. Early European settlers once used its seeds to prepare an admittedly inferior substitute for coffee. This was a risky practice, however, because the seeds contain a toxin that must be neutralized through proper roasting. One of the notable features of this tree is the very large doubly compound leaves that can exceed 2 feet in length and almost that in breadth. Many people remark that the tree has an almost tropical appearance when the leaves are out. The female specimens of flowering age (the sexes occur on separate trees) are instantly recognizable by the presence of hanging 6-to-9-inch dark thick-skinned seed pods that remain on the tree through the winter, almost giving the impression of roosting birds. The pods — the classic fruit of plants in the legume family — are initially green and turn brown when ripe but don’t release their very hard seeds until they’ve lain on the ground for some time.
The twigs are very stout, and when not in leaf give the tree a stubby look which is somewhat unattractive on nursery saplings. However, as they mature the trees gradually gain elegance and a strong individualistic architecture. Further softening the look of the thick twigs is the whiskery effect given by the typical winter persistence of the midribs of the large leaves. Kentucky coffee tree bark is unusual with narrow plates that tilt up along one edge. The tree is very adaptable to Front Range conditions and is notably tolerant of soil alkalinity. It’s one of the latest trees to leaf out in spring. In the fall, the foliage usually turns a bright yellow.
Until recently the tree found a place mainly in park settings where the pod litter was more manageable whenever young seedlings turned out to be females. However, the nursery industry began producing grafted male trees that have gained currency for use on residential properties and on tree lawns. A curious fact about this tree is that it was the state tree of Kentucky from 1976 to 1994, when it was replaced by the tulip tree, which is what it had been prior to 1976.