Honeylocust (Gleditsia triacanthos): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table.

At a glance

Item	What the source records
Scientific name	Gleditsia triacanthos L., legume family (Silvics)
Other names	Sweet-locust and thorny-locust (Silvics)
Native status, USDA PLANTS	Native in Canada and in the lower 48 states
Natural size, Silvics	In natural stands 21 to 24 m (70 to 80 ft) tall and 61 to 91 cm (24 to 36 in) in diameter; on the best sites 43 m (140 ft) and 152 to 183 cm (60 to 72 in)
Age, Silvics	Relatively short lived, reaching 125 years
Green weight of the wood, NRS-38	60 lb per cubic foot, without bark

Native range and where it grows

The Silvics of North America handbook (Agriculture Handbook 654, 1990) says honeylocust is found scattered across the east-central United States, in a range that runs from central Pennsylvania to southeastern South Dakota, then through central and southeastern Texas and southern Alabama, and back northeast to western Maryland. It lists outlying populations in northwestern Florida, west Texas and west-central Oklahoma, and says the tree is naturalized east to the Appalachians from South Carolina north to Pennsylvania, New York and New England. The handbook puts its best development in the valleys of small streams in southern Indiana and Illinois.

Silvics calls honeylocust typically a bottom land species on moist fertile soils near streams or lakes, and also on soils that come from limestone. It says growth is poor on gravelly or heavy clay soils. Over its range the tree grows naturally below 610 to 760 m (2,000 to 2,500 ft), and the general upper limit is reported as 1,520 m (5,000 ft). The handbook describes it as very resistant to drought and tolerant of acid and alkaline soil and of soil salinity, with best development at a pH between 6.0 and 8.0. In natural stands it is generally only a minor part of the forest and appears in four forest cover types, including Bur Oak and Willow Oak-Water Oak-Diamondleaf Oak.

Flowers, pods and seed

Silvics says flowering comes in late spring, on average about May 10 at the southern limit of the range and June 25 in the north, when the leaves are nearly full grown. The species is polygamo-dioecious, with flowers in dense green racemes. Seeds are borne in flat, often twisted pods 15 to 41 cm (6 to 16 in) long that ripen about mid-September in the south and mid-October in the north. The handbook says a tree begins bearing seed at about 10 years, with the best production between 25 and 75 years, and that the seed coats are impermeable, so seed stays viable for long periods. It says cattle eat the pods and spread the seed, and that the pods are sweet and eaten by livestock and wildlife.

Thorns, growth and roots

Silvics says thorn production usually fades in the upper and outer crown as the tree ages, while thorns may appear on the lower trunk and on sprouts. It says the thornless variety has been planted in many cities as a replacement for elm, and that the tree is widely cultivated as an ornamental and shade tree in all countries with a temperate climate. Young trees planted in shelterbelts from North Dakota to Texas grew on average 49 cm (19.2 in) a year in height over the first 7 years. The handbook describes the root system as deep and widely spreading, with a strong taproot, reaching 3 to 6 m (10 to 20 ft) in deep soils. It classes the tree as intolerant of shade.

Wood

The Wood Handbook (FPL-GTR-282, 2021) says the sapwood is generally wide and yellowish, in contrast to light red to reddish-brown heartwood. It calls the wood heavy and hard, strong in bending and stiff, with good shock resistance and lasting qualities in ground contact, and says it is little used because of its scarcity, mostly locally for fence posts and general construction.

Wood Handbook figure	Green	At 12% moisture content
Specific gravity (Table 5-3b)	0.60	Not published
Modulus of rupture, lbf per square inch (Table 5-3b)	10,200	14,700
Side hardness, lbf (Table 5-3b)	1,390	1,580

The green weight is in the NRS-38 table, the same figure used in the log weight calculator.

Insects and diseases the handbook names

Silvics says attacks by insects have grown along with plantings, particularly of thornless cultivars, and that they are generally not fatal but weaken the tree and slow growth.

Leaf feeders. The mimosa webworm, which Silvics calls severe and widely distributed, spider mites, the whitemarked tussock moth, the honeylocust plant bug, a leafhopper, bagworms and the walkingstick.
Borers and girdlers. A flatheaded borer important west of the Mississippi River, the wood borer Xyleborus saxesenii, the twig girdler, and a bruchid weevil that feeds on the seed. The periodical cicada can damage young transplanted trees by laying eggs in twigs.
Scales. The European fruit lecanium and the cottony maple scale, which injure the bark of small branches. The cottony maple scale page sets out what extension services record for that insect, and bagworm has its own page.
Diseases. Silvics says honeylocust has few diseases that interfere with growth except in isolated situations. It names the canker Thyronectria austro-americana as the most noteworthy and potentially fatal, tarry leaf spot as the most widely distributed leaf disease, cotton root rot in seedlings, two Ganoderma root rots, and heart-rot fungi.

The handbook adds that the tree was visibly damaged but not killed by air pollution in southeast Texas, was ranked highly resistant to ice damage in Illinois, and is easily damaged by fire because of its relatively thin bark. For who takes reports of regulated pests, see reporting a pest in the United States. Pests and diseases by country sets out which ones agencies regulate, and pesticide licences by country says who may apply pesticides.