Honey Locust

Honey Locust Gleditsia triacanthosHoney locust (Gleditsia triacanthos), also known as thorny locust or thorn tree, is a medium sized tree with pleasing, graceful foliage. The leaves are alternate, and both compound and double compound leaves on the same plant. The leaflets are 3/4 to 1 1/2 inches long, with small widely spaced teeth. Buds are mostly embedded in the branch with only the tips protruding.

Habitat: Found in bottomland woods, old pastures, and sandy prairies. Common throughout most of Iowa.

honey locust tree in the winter with no leaves
Honey Locust Tree - Photo by Paul Way, Iowa State University

Hardiness: Zones 4 through 9. Most cultivars do not perform well in the heat, humidity, and heavy soils.

Growth Rate: Fast. As a young tree, it will grow 2 feet or more per year over a ten year period.

Mature Shape: Upright, spreading. Very delicate and sophisticated silhouette.

Height: 70-80 feet

Width: 20-40 feet

Site Requirements: Adaptable to most soils. Readily transplanted. One of our most adaptable native trees.

Leaves: Alternate, compound, with thorns or spines

Flowering Dates: May - June

Seed Dispersal Dates: September - Winter

Seed Bearing Age: 10 years

Seed Bearing Frequency: Generally every year, with abundant crops every year or two

Seed Stratification: Place seeds into boiling water and allow to cool overnight.

Twigs are slender, shiny, greenish brown to reddish brown. Older twigs, branches and the trunk are armed with single or three-branched or more thorns four to eight inches long. Trees without thorns make up approximately 10% of the natural population. The bark of honey locust is dark red-brown and fairly smooth; on older trees it breaks into long, thin, flat, longitudinal ridges with curled edges.

Many selections of this species have been make for urban use because of its open foliage, tolerances to the urban environment and fairly fast 
growth rate. 

Honey locust is a non-nitrogen fixing member of the legume family. Once considered to be relatively free of insects and disease pests, in recent years Mimosa webworm, cankers, and borers have become more common. Its sharp formidable thorns have and continue to be a major deterrent in the propagation and management of this species. Most landowner manage against this species and consider it a weed species which should be remove from most woodlands.

The reddish wood is strong, coarse grained and moderately durable. Its common uses have included fence post, railroad ties, furniture, interior woodwork and fuel wood.

side by side views of honey locust trunks showing bark and thorns
Honey Locust Bark - Photos by Paul Wray, Iowa State University

Diseases that Can Affect Honey Locust

Insects that Can Affect Honey Locust


long cluster of green honey locust flowers
Honey Locust Flowers, Photo by Paul Wray, Iowa State University

long dark honey locust pods/fruit
Honey Locust Fruit - Photo by Paul Wray, Iowa State University

side by side images of honey locust twigs showing variation in color from brown to red
Honey Locust Twigs - Photos by Paul Wray, Iowa State University

side by side views of light green and dark green honey locust leaves
Honey Locust Leaves - Photos by Paul Wray, Iowa State University