The Kentucky coffee tree, also known as American coffee berry, Kentucky mahogany, nicker tree, and stump tree, is a tree in the subfamily Caesalpinioideae of the legume family Fabaceae, native to the Midwest, Upper South, Appalachia, and small pockets of New York in the United States and Ontario in Canada.
The Kentucky coffeetree is a moderately fast-growing tree, and male trees are often grown in parks and along city streets for ornamental purposes. The tree is typically fairly short-lived, healthy trees living from 100 to 150 years. The wood from the tree is used by cabinetmakers and carpenters. It is also planted as a street tree.
The Kentucky Coffee Tree is deciduous tree and grows to a height of 60 to 70 feet (18 to 21 meters) and a width of 40 to 50 feet (12 to 15 meters). It has an open, irregular crown. The tree’s branches are contorted. The twigs are stout and have small, bronze-colored buds that are partially sunken beneath the bark. The terminal bud is absent. Like the Sumac, branches are absent of fine spray; smaller branches are thick and lumpish.
This has large, bipinnately compound leaves that can grow up to 3 feet long and 2 feet wide. Each leaf consists of 5 to 9 pairs of pinnae (leaflets), with each pinna having 3 to 7 pairs of leaflets. The leaflets are oval-shaped, with a pointed tip and a rounded base, measuring 1½ to 3½ inches long and ¾ to 1½ inches wide. They are dark green in color and have a mild yellow fall color.
The leaves emerge in late spring, and the tree is one of the last to leaf out. The leaves turn yellow in the fall and drop early, leaving the tree bare for up to 6 months. The large size of the leaves and their early drop make them a potential source of litter.
The bark of the Kentucky Coffee Tree is rough and scaly, with deep zig-zag fissures running up the length of the tree trunk. On the outside, the bark has an ash-gray/green color, but the inside fissures are a light brown clay color. As the tree grows, its bark will start to look more and more like it is peeling.
The tree produces small, greenish-white flowers. These flowers bloom in May and June and are star-shaped, measuring approximately 1 inch (2.5 cm) in diameter. They are arranged in large panicles, which are clusters of flowers. Theis tree produces flowers in both male and female trees. Male flowers are small, greenish-white clusters that measure about 3 to 4 inches (10 cm) long. Female tree flower clusters can grow to be 8 to 12 inches (20 to 30 cm) long and are also greenish-white. These flowers are not particularly showy or colorful, but they play an important role in the tree’s reproductive process.
The seed pods of the Kentucky Coffee Tree are thick and leathery, measuring between 5 to 10 inches. They contain three to nine seeds each, with each seed measuring 1.5 to 2 cm long. The pods make a rattling sound when they are immature and sway in the wind. The seeds are toxic when raw, but they can be roasted and used as a coffee substitute.
The Kentucky Coffee Tree thrives in moist, well-drained soils, and is often found in floodplains, along riverbanks, and in rich woodlands. This tree is tolerant of a wide range of soil conditions, from sandy loam to clay, and can adapt to various habitats. It prefers full sun but can also tolerate partial shade. The USDA hardiness zones for the Kentucky Coffee Tree range from 3B through 8B.
Key Characteristics
- The Kentucky Coffee Tree is native to the Midwest and central United States.
- It has large, bipinnately compound leaves that grow up to 1 meter in length, with many pairs of sharply pointed, egg-shaped leaflets.
- The tree blooms in June with spike-like flower heads that are open and grow from the ends of the branches.
- The flowers have petals that are 8-10mm long, oblong or inversely lance-shaped.
- The seed pods are oblong, flattened, 8-25cm long and 3-5cm wide, with seeds that are 10-15mm long, bean-shaped, thick and hard.
- The Kentucky Coffee Tree is a part of the legume family, Fabaceae, and is the only native tree in the genus Gymnocladus.
- It is a robust tree that can grow up to 6-70 feet tall and 40-50 feet wide.
- It is often used as a shade tree due to its open, irregular crown and distinctive appearance.
- The tree is tolerant to a wide range of soils and pollution, making it suitable for urban environments.
- In times, the roasted seeds were used as a coffee substitute, and the plant is sometimes cultivated as an ornamental.
- The strong heavy wood is used in cabinetry and general construction.
- The Kentucky Coffee Tree grows to about 30 metres tall.
Cultivation
- Choose a location that receives full sun to partial shade. This can tolerate a wide range of soil types, including clay, loam, and sand, but it prefers well-drained soil.
- Plant your tree in spring or fall when the soil is warm and moist. This gives the tree time to establish its roots before the next season.
- Dig a hole twice as wide and deep as the root ball of your tree. Place the tree in the hole, ensuring that the top of the root ball is level with the ground. Backfill the hole with the same soil you removed, tamping it down gently. Water the tree thoroughly after planting.
- Water your tree regularly, especially during the first year after planting. Aim for about 1 inch of water per week, either from rainfall or supplemental irrigation. Once established, the tree is relatively drought-tolerant.
- Fertilize your tree annually in the spring with a balanced, slow-release fertilizer. Follow the package instructions for the correct amount to apply based on the size of your tree.
- Prune your tree in late winter or early spring before new growth begins. Remove any dead, diseased, or damaged branches. You can also prune to maintain the desired shape and size of the tree.
- This is relatively pest- and disease-resistant. However, watch for common issues like leaf spot and canker. Treat these with appropriate fungicides or by removing affected branches.
- In colder climates, consider wrapping the trunk of your Kentucky Coffee Tree with a tree wrap to protect it from sunscald and frost cracks. Remove the wrap in spring.
- Apply a layer of organic mulch around the base of your tree to help retain moisture, regulate soil temperature, and suppress weeds. Keep the mulch a few inches away from the trunk to prevent rot.