Honey Locust

Plant honey locusts in full sun in almost any soil type, including heavy clay, sandy, alkaline, and compacted urban soils. Their exceptional adaptability makes them ideal for challenging sites. Space trees 30 to 40 feet apart for shade planting. Always select thornless, podless cultivars such as Shademaster or Sunburst for landscape use, as wild-type trees have dangerous thorns and produce messy seed pods.

Water newly planted trees deeply once a week during the first growing season. Honey locusts are among the most drought-tolerant shade trees once established and rarely need supplemental irrigation. Apply a 2 to 3 inch layer of organic mulch over the root zone. The fine compound leaves cast light, dappled shade that allows turf grass and perennials to grow beneath the canopy.

Prune in late winter to maintain a strong central leader and remove any crossing or dead branches. Honey locusts develop a naturally open, spreading crown that requires relatively little corrective pruning. Watch for webworm and mimosa webworm damage in summer. The tiny leaflets break down rapidly in autumn and rarely require raking, which is a significant advantage over most shade trees.

The honey locust (Gleditsia triacanthos) is native to the central United States, with its natural range stretching from Pennsylvania westward to Nebraska and southward to Texas and Mississippi. It thrives along river bottoms, floodplains, and woodland edges throughout the Mississippi and Ohio River valleys, where it grows alongside oaks, hickories, and other hardwoods in rich alluvial soils. The species was first formally described by Carl Linnaeus in 1753, with the genus name honoring Johann Heinrich Gleditsch, a German botanist and contemporary of Linnaeus. The specific epithet triacanthos means 'three-thorned,' referring to the frequently three-branched thorns found on the trunk and older branches of wild specimens. Native American peoples across its range made extensive use of the tree. The Cherokee, Creek, and other southeastern nations consumed the sweet pod pulp as a food, brewed it into a beverage, and used bark preparations medicinally. Early European settlers quickly recognized the tree's value, using its durable wood for fence posts and its pods as livestock fodder. The pods contain a sweet, honey-like pulp with up to 30 percent sugar content, which gives the tree its common name. By the nineteenth century, honey locust had been widely planted beyond its natural range as a living fence due to its impenetrable thorns. The development of thornless and podless cultivars in the mid-twentieth century transformed it into one of the most popular urban street and shade trees in North America. Its fine-textured foliage casts a light, dappled shade that allows turfgrass to grow beneath it, and its tolerance of pollution, salt, compacted soil, and drought make it ideally suited to challenging urban environments.

Honey locusts thrive in an extraordinarily wide range of soils, from heavy clay to sand, and tolerate pH levels from 5.0 to 8.5. They are one of the few shade trees that perform well in strongly alkaline and saline soils. Young trees benefit from a balanced 10-10-10 fertilizer applied in early spring. Mature trees rarely need supplemental fertilization due to their nitrogen-fixing root nodules that improve soil fertility. Avoid over-fertilizing, which promotes succulent growth susceptible to frost and pest damage.

Honey locusts are primarily grown as ornamental shade trees, and thornless podless cultivars produce no harvestable material. Wild-type honey locust trees produce long, twisted brown pods in autumn that contain a sweet pulp historically used as animal feed and occasionally as a human food source. Pods should be collected after they fall from the tree in late autumn. The pulp has a sweet, honey-like flavor that can be extracted by soaking pods in water.

Seed pods from wild-type honey locusts can be stored in burlap sacks in a dry, cool location for several months. The sweet pulp can be separated from the seeds and dried or processed into a syrup by boiling the pods in water and straining. Dried pods keep for over a year in airtight containers. The extremely hard, durable wood is prized for fence posts and outdoor construction due to its natural rot resistance. Seeds remain viable for years when stored dry and cool.