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Gleditsia spp.

honey locusts

Fabaceae North America, Asia, South America

Attracts Pollinators Drought Tolerant Fragrant (moderate)

Native to North America

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 3–9

Overview

Gleditsia spp. is a genus of about 12 species of deciduous trees in the legume family, Fabaceae, native to North America, eastern and central Asia, and parts of South America. Trees reach 30 to 100 feet (9 to 30 m) tall with broad, open, spreading crowns. The leaves are pinnately or bipinnately compound, divided into many small leaflets that cast light, filtered shade and turn yellow before dropping in autumn. Trunks and branches of most species bear stout branched thorns, sometimes several inches long, though thornless forms occur. Small greenish flowers open in early summer in narrow clusters and are followed by flattened pods 6 to 18 inches (15 to 45 cm) long that twist as they dry; in G. triacanthos the pod pulp is sweet, the source of the name honey locust. The genus grows in floodplains, woodland edges, and open ground, tolerating drought, salinity, compacted soil, and a wide pH range. A limitation is the thorns and abundant pods of the wild forms, which create litter and hazard, leading to the selection of thornless, podless cultivars for landscape use.

Native Range

Gleditsia spp. is native to North America, eastern and central Asia, and South America. G. triacanthos is native to the central United States, while other species occur in China, Japan, the Caspian region, and Argentina, typically in moist bottomlands and open woodlands.

Suggested Uses

Gleditsia spp. is used as a shade and street tree, particularly thornless cultivars of G. triacanthos, which cast light, filtered shade over lawns, patios, and paved areas. The open canopy and tolerance of harsh sites suit urban plantings, parking islands, and reclaimed ground.

How to Identify

Identify Gleditsia spp. by its pinnately to bipinnately compound leaves with many small oval leaflets, its open, spreading crown, and the stout, often branched thorns on the trunk and older branches of wild forms. The long, flattened, twisting seed pods, 6 to 18 inches (15 to 45 cm) long, persist into winter and separate the genus from the similar Robinia spp., which has shorter pods and paired spines.

Appearance

Size & Dimensions

Height30' - 100'

Width/Spread25' - 70'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring Summer

Gleditsia spp. flowers in late spring to early summer, roughly May and June. The small greenish-yellow flowers are borne in slender clusters and are fragrant in several species. Pods develop over summer and ripen brown to mahogany by autumn, persisting on the tree into winter.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

clay loam sand

Drainageaverage

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

20-30 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Across the genus, Gleditsia spp. grows in full sun and adapts to a wide range of soils, from sandy to clay, and a soil pH of about 6.0 to 8.0. Established trees tolerate drought, road salt, and urban compaction, which suits street and parking-lot plantings. Young trees are watered through the first two or three seasons to establish a deep root system. The light, filtered canopy allows turf and underplantings to grow beneath. Several pests and diseases affect the genus, including borers, webworm, and canker, with pressure varying by region and cultivar. Thornless, fruitless cultivars of G. triacanthos are grown where pod and thorn litter would be a problem.

Pruning

Pruning is done in late winter while the tree is dormant to remove crossing, dead, or damaged branches and to develop a strong central structure. Young trees respond to formative pruning that spaces the main limbs. Large pruning cuts can be slow to close and may admit canker, so branch removal is kept to smaller diameters where possible.