Botanical Name: Gleditsia triacanthos var. inermis ‘Impcole’
The Imperial Honeylocust (Gleditsia triacanthos var. inermis ‘Impcole’) is a cultivar of the Honey Locust (Gleditsia triacanthos), a tree that is native to the eastern and mid-western United States. Gleditsia is named after a director of the botanical gardens in Berlin in the eighteenth century, Johann Gottlieb Gleditsch.
‘Inermis’ is a thornless variety that is found growing naturally. Most cultivated varieties are thornless as most consumers desire trees without thorns. The Imperial Honeylocust is one of the smaller honey locust cultivars available. It grows to a height of 30-40 feet and has a spread of 25-35 feet. It is also an almost seedless variety and grows in a compact vase-shaped form with a flat top.
The leaves of the Imperial Honeylocust are an attractive dark green and pinnately or bipinnately compound. They are ovate in shape and grow to 0.5 to 1.5 inches long. These leaflets give the tree a beautiful fine texture. The Imperial Honeylocust puts on a brilliant yellow foliage display in the fall.
The Imperial Honeylocust is not particular about the soil it grows in or its pH level. It is tolerant of many different environmental conditions such as heat and wind. It has exceptional resistance to urban pollution, as well as drought conditions. This tree, therefore, thrives in city landscapes. It is also a deer resistant plant. It is, however, susceptible to branches breaking during ice storms.
Height: 30-40 ft.
Width: 25-35 ft.
Flower Color: Greenish Yellow, Greenish White
Flowering Time: May-June
Fall Color: Yellow
Features: Superior fall color, fine textured foliage
Exposure: Full Sun
Watering: Moderate & Regular
Soil: Prefers rich, moist, well-drained soil, but tolerant of a wide range of soils and pH.
Growth Rate: Fast
USDA Zones: 3-8
Uses: Street tree, urban landscapes, park tree, shade tree
Similar trees: Gleditsia triacanthos var. inermis 'Shademaster' (Shademaster® Honeylocust), Gleditsia triacanthos var. inermis 'Skycole' (Skyline® Honeylocust), Gleditsia triacanthos var. inermis 'Suncole' (Sunburst® Honeylocust)