Cladrastis

Description

Cladrastis is a genus of flowering trees in the legume family, Fabaceae. It is native to North America and Asia, and comprises two species: Cladrastis kentukea, commonly known as American yellowwood, and Cladrastis lutea, commonly known as Chinese yellowwood. Cladrastis trees are prized for their beautiful, fragrant, and showy flowers that bloom in spring and often attract bees and butterflies.

Taxonomic Information

Appearance

Cladrastis trees are deciduous and can grow up to 50 feet tall and 40 feet wide. They have a rounded or oval shape and a moderate growth rate. Cladrastis leaves are pinnate, with 7-9 oval or lance-shaped leaflets that are up to 5 inches long. In fall, the leaves turn a beautiful yellow color. Cladrastis flowers are fragrant and showy, with clusters of white or yellowish-white flowers that bloom in spring. The flowers are followed by flat, brown seed pods that are up to 5 inches long and contain several seeds.

Care Guide

To care for a Cladrastis tree, provide it with well-draining soil that is rich in organic matter. Water it deeply once a week, especially during hot and dry weather. Fertilize it in early spring with a balanced fertilizer that is high in nitrogen. Cladrastis trees prefer full sun or partial shade and can tolerate a wide range of temperatures, from -20°F to 100°F. They are hardy in USDA zones 4-8.

Common Pests & Diseases

Cladrastis trees are generally healthy and resistant to pests and diseases. However, they can be affected by cankers, leaf spots, powdery mildew, and webworms. To prevent these problems, keep the tree well-watered and avoid overhead watering. Prune off any infected branches and dispose of them properly.

Habitat

Cladrastis kentukea is native to the southeastern United States, where it grows in moist woodlands and along streams. Cladrastis lutea is native to China, Korea, and Japan, where it grows in mountainous regions and along rivers. Both species prefer well-draining soils and can tolerate a wide range of temperatures.

Question and Answer

Q: How do you propagate Cladrastis trees?

A: Cladrastis trees can be propagated from seeds, cuttings, or grafts. Seeds should be planted in fall, while cuttings can be taken in summer and rooted in a well-draining soil mix. Grafting is the most reliable method for producing clones of desired cultivars.

Q: What is the best time to prune a Cladrastis tree?

A: The best time to prune a Cladrastis tree is in late winter or early spring, before new growth begins. Prune out any dead, damaged, or diseased branches, as well as any crossing or rubbing branches. Avoid pruning in fall, as this can stimulate new growth that may not have time to harden off before winter.

Q: Are Cladrastis trees deer-resistant?

A: Cladrastis trees are generally not deer-resistant, as deer may browse on the leaves, flowers, and young stems. To protect your Cladrastis tree from deer, consider using fencing, repellents, or other deterrents.

Q: How long do Cladrastis trees live?

A: Cladrastis trees can live up to 100 years or more, depending on the growing conditions and care they receive. With proper pruning, fertilization, and watering, your Cladrastis tree can provide beauty and shade for generations to come.

Related Plants

Other members of the Fabaceae family that are related to Cladrastis include:

• Sophora
• Robinia
• Cercis
• Laburnum

References

• Dirr, M. A. (2009). Manual of woody landscape plants: their identification, ornamental characteristics, culture, propagation and uses.
• Huxley, A., Griffiths, M., & Levy, M. (1999). The new Royal Horticultural Society dictionary of gardening.
• Missouri Botanical Garden. (2021). Cladrastis kentukea.
• North Carolina State University. (2021). Cladrastis lutea.