The Kentucky coffee tree (also known as Kentucky coffeetree) got its name for the small brown fruits that emerge from its long cylindrical seed pods that, when they ripen and then dry, resemble coffee beans. It's also said that Native Americans (particularly the Fox, Winnebago, and Pawnee communities) and early settlers in the Kentucky Territory used to roast the beans to make a hot beverage. However, the raw seed pods are toxic and should be avoided. Wildlife do not eat the seed pods. Nature scientists speculate that very large prehistoric mammals such as giant sloths and mammoths dispersed the seeds over a wider ranging area. The wood of this tree was once used to build railway sleeper cars. Its habitat range is throughout the central United States, from Pennsylvania to Kentucky and further north to Michigan and Minnesota.
This tall, majestic tree is becoming more and more popular as an ornamental landscape tree for parks, golf courses, and large open areas. It has enormous leaves (up to 2 feet wide) making a dramatic impact in the landscape once it reaches its full mature height. The Kentucky coffee tree is also resistant to drought and not bothered too much by air pollution, and it makes an excellent shade tree, making it a good choice for urban areas with space for it to grow and spread out. It leafs out rather late in spring, then produces pale green flowers that grow in panicle-like clusters. The female trees bear flowers said to have a fragrance similar to roses. The scaly grey bark has a rough texture. The seed pods add more interest in autumn, as do the bare branches that emerge when the tree drops its leaves rather early (the Greek genus name means "naked branch"), after they shift from green to a warm yellow color. The spreading branches create a bold shape (some call it a perfect "Halloween tree") in the fall and winter landscape, making this a decorative tree for all seasons. From 1976 until 1994, it was the official state tree of Kentucky, but was then replaced by the Tulip Poplar.
|Common Name||Kentucky coffee tree|
|Botanical Name||Gymnocladus dioicus|
|Plant Type||Perennial deciduous tree|
|Mature Size||65-75 ' tall, 40-50' spread|
|Sun Exposure||Full sun|
|Soil Type||Tolerant of clay, likes loam|
|Soil pH||Acidic, alkaline or neutral|
|Bloom Time||Late spring|
|Flower Color||Greenish white|
|Hardiness Zones||3-8, USA|
|Native Areas||Central US, Nebraska to Pennsylvania|
|Toxicity||Seeds are toxic to people|
Kentucky Coffee Tree Care
This is a fairly easy-care tree that is adaptable to a wide range of soil conditions. It's somewhat slow growing and short-lived, reaching between 100 to 150 years of age on average.
The Kentucky coffee tree does best with at least 6 hours of direct sunlight.
Adaptable to a wide range of soil conditions, this tree does as well in clay but may thrive a bit better in sandy loam. It isn't bothered by too much acidity or alkalinity. Being drought-tolerant, it's also fine in dry spots. Too much wet soil may affect the roots over time, so planting too near a swap or marshy spot is not a good idea.
In times of extended drought, this tree will benefit from some additional watering at its base. But otherwise it's very drought-tolerant and should not require extra water.
Temperature and Humidity
Kentucky coffee tree isn't too fussy about temperature or humidity and is very winter hardy. It's not likely to well in growing zones higher than 8.
Fertilize the Kentucky coffee tree with fertilizing products that promote woody, strong growth rather than excessive foliage growth. Avoid fertilizing with nitrogen products, since the tree is a nitrogen fixer. (It even works to supply neighboring plants with nitrogen.)
Types of Kentucky Coffee Tree
There are several cultivars available through the nursery trade, most of them male, which do not produce fruit. They therefore produce less pod litter, making them more suitable for smaller urban settings such as streets and small parks.
- Espresso: This grafted seedless variety is one of the most popular male cultivars available. The arching branches form a vase shape and the compound leaves make it a desirable shade tree.
- Prairie Titan: This is another male fruitless cultivar with an upright spreading shape. The foliage tends to be more bluish-green than other cultivars.
- Stately Manor: This male cultivar has a more narrow upright form, but the spread may still reach up to 50 feet wide at maturity.
The best time for pruning the Kentucky coffee tree is late winter or early spring, after the worst cold temperatures are no longer a danger. Its slow growth habit means that young trees won't need any pruning in the first few years, unless the branches become damaged. However, if overly long (thereby weaker) branches develop, these should be pruned when young to promote a stronger structure.
How to Grow Kentucky Coffee Tree From Seed
Kentucky coffee tree is fairly easy to grow from seed. First you must file the seed coating by hand with a small file, and then soak the seeds in water for 24 hours. This will allow for a more rapid germination.
Propagating Kentucky Coffee Tree
This tree is easy to grow from dormant root cuttings from December through March.
Common Problems With Kentucky Coffee Tree
This tree has no real disease or insect problems to worry about. "Leaf litter" can be a problem as the leaves are very large, and the fallen seed pods beginning in spring can also create a bit of a mess. This makes it a better candidate for parks or other open areas rather than as a street tree.
Is the Kentucky coffee tree easy to care for?
Though there's a tendency towards leaf litter, from the very large leaves, male cultivars do not bear seed pods making seasonal clean up much easier.
How fast does the Kentucky coffee tree grow?
This tree has a fairly slow growth rate, between 12" and 24" per year on average.
How long can a Kentucky coffee tree live?
In some cases these trees can live to be 150 years old, but they're usually considered to have about a 100 year life span, depending on factors such as growing conditions, weather damage, drought, etc.
Graper, David. "Kentucky Coffeetree". South Dakota State University Extension, 2019, https://extension.sdstate.edu/kentucky-coffeetree.