Thornless Common Honeylocust Gleditsia triacanthos var. inermis

The Thornless Honey Locust is a large, deciduous, shade tree that is a "thornless" variety of the species, Gleditsia triacanthos, commonly known as the Honey Locust. It is a member of the Fabaceae or legume family and grows 30 to 40 feet tall and 25 to 40 feet wide with an upright oval or rounded habit. This variety can be found growing in the wild and reaches the same height as its thorny species trees. Many of the cultivars of this variety are sold in commerce and typically do not have thorns and many times do not have seedpods. This tree has pinnate to bipinnately compound. dark green leaves with ovate leaflets. In the fall, the leaves turn yellow. 

 It is native to central and eastern North America, from North Carolina to Mexico. It grows in the piedmont, mountain, and coastal regions of North Carolina.

As the name implies, it does not have the thorns of its parent plant Gleditsia triacanthos. The genus, Gleditsia, is named for the 18th century, German botanist, Johann Gottlieb Gleditsch, who was director of the Botanical Garden of Berlin. The specific epithet, triacanthos, is derived from the Greek word, acantha, which means thorn, and tri, meaning three. This references the 3-branched or 3-spined thorns found on this species' tree. The infraspecific epithet, inermis, is Latin for unarmed or without thorns or spines. A part of the common name, honey, is derived from the honey-like substance found in the pods

Plant this tree in locations that receive full sun and have moist, organically rich, well-drained soil. This tree tolerates a variety of soil conditions including compaction, poor soils, drought, and flooding. It is also tolerant of heat, urban conditions, salt, and black walnut. and is resistant to damage by deer. Be sure that you have enough room for the tree's mature size. It transplants easily and is best done in the fall.

With a short trunk and open, spreading crown, the fine-textured leaves give it a delicate silhouette. This flowering tree casts light shade allowing grass to be planted underneath, and when the tiny leaflets turn bright yellow and drop in the fall, it results in the easy cleanup. Some cultivars are fruitless making for even easier cleanup. The wood from this tree is often used for fence posts, railroad ties, furniture, tool handles, and fuel.

The Thornless Honey Locust is a finely textured, urban-tolerant, fast-growing, and filtered shade tree. Use it as a specimen in a lawn, recreational play area, or as a street tree. The fruit is edible by wildlife, which attracts pollinators and makes it a welcome addition to any wildlife garden. Its lack of thorns; therefore, makes it an ideal shade tree for a children's garden. 

Seasons of Interest:

Bark:  Winter    Bloom: Late Spring to Early Summer    Foliage:  Late Spring, Summer, and Fall           Fruits:  Fall

Quick ID Hints:

• Adult leaves pinnately compound
• Juvenile leaves bipinnately compound
• Fruit is a dark brown, pendulous pod, often curved or coiled
• Short trunk, fine-textured, spreading crown
• Pubescent midrib on the leaf underside
• 20 to 30 leaflets per leaf

Insects, Diseases, and Other Plant Problems:  Borers, gall midge, and webworms may be problems. Other pests include leafhoppers, leaf miners, and spider mites. The leaves may be deformed by the honey locust pod gall midge and can cause small branches to die. Honey locusts are susceptible to honey fungus, leaf spots, canker, witches’ broom, powdery mildew, and rust.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

More information on Gleditsia triacanthos.