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

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

Family:

Fabaceae (Bean Family) 48

Genus:

Gleditsia (Honeylocust) 5

Plant Type:

Tree 581

Hardiness:

USDA Zone 4 498

Deciduous / Evergreen:

Deciduous 809

Flowers:

Yellow (Spring; not ornamentally important)

Foliage:

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

Fruit:

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

Ultimate Height:

30-40 feet

Ultimate Spread:

25-35 feet

Light Requirements:

Soil:

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.

Special Characteristics:

Foliage Characteristics 279

Fall Color 214

Bark 161

Drought Tolerant 278

Salt Tolerant 60

Tolerant of Poor Site Conditions 190

Shade Tree 173

Specimen 603

Street Tree 130

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.