Gleditsia triacanthos var. inermis

Thornless honey locust is a large deciduous tree in the Fabaceae (bean) family, reaching heights of up to 30 to 70 feet quickly. As the name implies it does not have the thorns of its parent plant Gleditsia triacanthos.  Gleditsia is named for the German botanist Gottlieb Gleditsch, triacanthos is Latin for 3-spined and inermis is Latin for unarmed.

With a short trunk and open, spreading crown the fine-textured pinnately compound leaves give it a delicate silhouette.   Place it in the full sun in moist, organically rich, well-drained soil, and make sure you have enough room for its mature size.

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 an easy clean up.  Some cultivars are fruitless making for even easier clean up. It transplants easily, tolerates poor clay soils, urban conditions, salt, drought, black walnut, and is resistant to damage by deer.

Use as a specimen in a lawn, recreational play area or as a street tree.  It attracts pollinators making it a welcome addition to any wildlife garden and its lack of torns make it an ideal shade tree for a children's garden.

Quick ID Hints:

• adult leaves pinnately compound
• juvenile leaves bipinnately compound
• fruit is dark brown, pendulous pod, often curved or coiled
• short trunk, fine-textured, spreading crown
• pubescent midrib on leaf underside
• 20-30 leaflets per leaf

Insects, Diseases, and Other Plant Problems:  Borers, gall midge, and webworms may be problems.  Honey locusts are susceptible to leaf spot, 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.