TREES & plants

Thornless honey-locust

Foliage of thornless honey-locust

The light, dappled shade cast by the lacy foliage of this attractive tree is only one of its virtues. It also is durable and adaptable, tolerating a wide range of soil conditions as well as drought, and road salt, and has a lovely yellow fall color. As a result, honey locust is overused in city and suburban landscapes. For the sake of species diversity, it should only be planted after careful consideration of alternatives. The native species of honey-locust has large thorns on its stems and bark. For this reason, thornless honey locust, also known as Gleditsia triacanthos f. inermis, is most commonly sold. 

Botanical name: 
Gleditsia triacanthos f. inermis
All Common Names: 
thornless honey-locust, common honey-locust, honeylocust, thornless honeylocust
Family (English): 
Family (Botanic): 
Fabaceae (formerly Leguminosae)
Tree or Plant Type: 
  • Tree
  • Deciduous (seasonally loses leaves)
Native Locale: 
  • Chicago area, 
  • Illinois, 
  • North America
Planting Site: 
  • Residential and parks, 
  • City parkway, 
  • Wide median, 
  • Restricted sites
Landscape Uses: 
  • Parkway/street, 
  • Shade tree, 
  • Specimen
Size Range: 
  • Large tree (more than 40 feet), 
  • Medium tree (25-40 feet)
Mature Height: 
30-70 feet
Mature Width: 
30-70 feet
Light Exposure: 
  • Full sun (6 hrs direct light daily)
Hardiness Zones: 
  • Zone 4, 
  • Zone 5 (Chicago), 
  • Zone 6, 
  • Zone 7, 
  • Zone 8, 
  • Zone 9, 
  • Zone 10
Soil Preference: 
  • Moist, well-drained soil
Acid Soils: 
  • Tolerant
Alkaline Soils: 
  • Tolerant
Salt Spray: 
  • Tolerant
Soil Salt: 
  • Tolerant
Drought Conditions: 
  • Tolerant
Poor Drainage: 
  • Tolerant
Planting Considerations: 
  • Commonly planted
Ornamental Interest: 
  • Fall color, 
  • Persistent fruit/seeds
Season of Interest: 
  • Early fall, 
  • Mid fall
Flower Color & Fragrance: 
  • Inconspicuous
Shape or Form: 
  • Broad, 
  • Round
Growth Rate: 
  • Fast
Transplants Well: 
  • Yes
  • Game birds, 
  • Migrant birds, 
  • Small mammals
More Information: 

Tree & Plant Care

Prune in fall or winter.

Disease, pests, and problems

Mites can lead to early leaf drop.
Cankers, root rot, and borers are potential problems (most commonly on stressed trees).

Disease, pest, and problem resistance

Tolerant of black walnut toxicity.

Native geographic location and habitat

C-Value:  2
Native to most of the lower Midwest and south to the Gulf coast.

Bark color and texture 

Bark is dark gray, breaking into long flat plates that curl along the edges.
The native honey-locust has long thorns on stems and bark; f. inermis does not.

Leaf or needle arrangement, size, shape, and texture

Pinnately compound or bipinnately compound, alternate leaves with 20 to 30 oval leaflets; each leaf about 6 to 8 inches long. Fall color is yellow.

Flower arrangement, shape, and size

Inconspicuous; small yellow-green flowers in spikes in spring.

Fruit, cone, nut, and seed descriptions

Flat, red-brown pod about 1 inch wide and several inches long; often curling; each pod contains several seeds.  Some cultivars are fruitless (seedless).

Cultivars and their differences 

“These plants are cultivars of a species that is native to the Chicago Region according to Swink and Wilhelm's Plants of the Chicago Region, with updates made according to current research. Cultivars are plants produced in cultivation by selective breeding or via vegetative propagation from wild plants identified to have desirable traits."

Imperial™ (Gleditsia triacanthos f. inermis 'Impcole'): A more compact cultivar (35 feet); will produce a few seed pods.

Moraine  (Gleditisia triacanthos f. inermis ‘Moraine’):  This tree is a seedless male cultivar. It has a graceful outline, with small dark green foliage that turns golden yellow in fall.

Northern Acclaim (Gleditsia triacanthos f. inermis 'Harve'):  A seedless male cultivar,  considered cold hardy to zone 3; good yellow fall color; drought tolerant; 45 feet tall.

Perfection (Gleditsia triacanthos f. inermis 'Wandell'):  A seedless male cultivar with good branch structure; 50 feet tall.

Skyline  (Gleditisia triacanthos f. inermis ‘Skycole’):  A male (fruitless) cultivar with a more pyramidal shape.

Street Keeper (Gleditsia triacanthos f. inermis 'Draves'):  Narrow, upright form (20 foot spread); will produce some seed pods.

Sunburst (Gleditsia triacanthos f. inermis 'Suncole'):  New foliage emerges yellow and matures to bright green; a seedless, male cultivar.

Gleditsia triacanthos f. inermis or Thornless honey-locust