gleditsia triacanthos matureI bought a Gleditsia triacanthos ‘Sunburst’ some years ago as a young plant through the post. It’s now about 2 metres tall and beginning to find its feet in Old School Garden. I love its bright yellow foliage which is a great contrast to the maroon foliage of plants like Lysimachia ciliata ‘Firecracker’.

Common name: ‘Honey Locust’ or ‘Thorny Locust’

Native areas: A deciduous tree native to central North America,  it is mostly found in the moist soil of river valleys ranging from southeastern South Dakota to New Orleans and central Texas, and as far east as eastern Massachusetts. It was introduced into Britain in 1700, with the cultivar ‘Sunburst’ introduced in the 1950’s.

Historical notes: The Honey Locust, despite its name, is not a significant honey plant. The name derives from the sweet taste of the legume pulp, which was used for food by Native American people, and can also be fermented to make beer. The long pods, which eventually dry and ripen to brown or maroon, are surrounded in a tough, leathery skin that adheres very strongly to the pulp within. The pulp—bright green in unripe pods—is strongly sweet, crisp and succulent in unripe pods. Dark brown tannin-rich beans are found in slots within the pulp. Honey locusts produce a high quality, durable wood that polishes well, but the tree does not grow in sufficient numbers to support a bulk industry; however, a niche market exists for honey locust furniture. It is also used for posts and rails since it takes a long time to rot. In the past, the hard thorns of the younger trees have been used as nails! The tree has been used in traditional Native American medicine.

Gleditsia triacanthos 'sunburst' in Old School Garden- with Lysimachia ciliata 'Firecracker' in front and Monarda 'Cambridge Scarlet' and Crocosmia 'Lucifer'
Gleditsia triacanthos ‘Sunburst’ in Old School Garden– with Lysimachia ciliata ‘Firecracker’ in front and Monarda ‘Cambridge Scarlet’ and Crocosmia ‘Lucifer’

Features: A large, oval and elegant tree growing to 20 metres plus and quick growing. It’s leaves resemble fronds and when mature, it looks most striking with its shiny, long seed pods. Leaves are bright green turning to golden yellow in autumn. The variety ‘Sunburst’ has bright yellow foliage in early summer and this turns greener as the season progresses.

Uses:  A wonderful choice for heavily polluted environments prone to vandalism and a good choice for parks and industrial areas, it is also a great garden tree, doing well on most types of soil. It’s fast growth rate and ease of transplanting make it a good choice for new gardens where shade or a feature is wanted relatively quickly. The tree needs careful handling though, because of its thorns (however, most cultivars are thornless). The cultivar ‘Sunburst” has gained the RHS Award of Garden Merit (AGM). This cultivar grows to 15-20 metres and has a rounded, rather spreading form, a good substitute for the rather more damage-prone Robinia pseudoacacia ‘Frisia’.

Gleditsia triacanthos - autumn colour
Gleditsia triacanthos – autumn colour

Growing conditions: The cultivars (e.g. ‘Sunburst’, ‘Skyline’, ‘Inermis’) are popular ornamental plants. It tolerates urban conditions, compacted soil, road salt, alkaline soil, heat and drought. The popularity is in part due to the fact that it transplants so easily, its fast growth rate and tolerance of poor site conditions. It is also great where shade is wanted quickly, such as new parks or housing developments, and in disturbed and reclaimed environments, such as mine tailings. It is resistant to gypsy moths but is defoliated by another pest, the Mimosa Webworm. Spider mites, cankers and galls are also a problem with some trees.

Gleditsia triacanthos 'Sunburst'
Gleditsia triacanthos ‘Sunburst’

Further information:

Wikipedia- Gleditsia triacanthos

RHS- Gleditsia triacanthos ‘Sunburst’

Barcham trees directory

Old School Gardener