Gleditsia triacanthos f. inermis 'Impcole' [sold as Imperial®]
Imperial Thornless Honeylocust

Gleditsia triacanthos f. inermis ′Impcole′ [sold as Imperial®] - Summer Habit

Family:

Fabaceae (Bean Family) 51

Genus:

Gleditsia (Honeylocust, Honey Locust) 7

Plant Type:

Tree 583

Growth Forms:

Upright 579

Hardiness:

USDA Zone 4 524

Deciduous / Evergreen:

Deciduous 850

Flower Notes:

Yellow (Spring; not ornamentally important)

Foliage Notes:

Green (Dark green pinnately compound summer foliage); Yellow (Pleasant, bright yellow fall coloration)

Fruit Notes:

Brown (Long (7-18"), interesting pods; 'Impcole' is low-fruiting)

Ultimate Height:

30-40 feet

Ultimate Spread:

25-35 feet

Light Requirements:

Soil Notes:

Widely adapted to soils

Range:

Cultivated origin

Diagnostic Characteristics:

Leaves alternate, pinnately or bipinnately compound, 6-8" long with pubescent rachis and leaflets only 0.3-1.5" long. Zig-zag branches with swollen nodes of a shining red to reddish to greenish-brown color. Fruits (when present) are 7-18" reddish-brown pods that persist. Bark is divided into flat plates, separated by deep ridges. The branches of 'Impcole' come out of the main trunk at 90 degree angles.

Purdue Plant Doctor

Parts and Problems of Honey Locust

Special Characteristics:

Drought Tolerant 289

Salt Tolerant 61

Tolerant of Poor Site Conditions 189

Additional Information

This rounded, compact, and low-fruiting cultivar has finely compound leaves that provide a pleasant, dappled shade in the summer. The thornless forma inermis is only sold in commerce, as the profuse thorns of the species type can be a liability. Mimosa webworm and locust mite are serious pests in the Midwest, and are becoming more serious (especially in areas tending toward monoculture). Can be controlled with spraying.