Native to central and eastern North America. Fast growing, especially when young, with upright trunk and spreading, arching branches. To 3570 ft. tall and 2535 ft. wide. Bright green, fernlike leaves to 10 in. long are divided into many oval, 34- to 112-in.-long leaflets. Late to leaf out; leaves turn golden yellow and drop early in fall. Incon- spicuous flowers are followed by broad, 1- to 112-ft.-long pods filled with sweetish pulp and hard, roundish seeds.
Foliage casts filtered shade, allowing growth of lawn or other plants beneath. Small leaflets dry up and filter into grass, decreasing raking chores, but pods make a mess in autumn. Trunks and branches of the species are formidably thorny. Honey locusts listed here, however, are selections of G. t. inermis, thornless honey locust, with no thorns and few or no pods.
These trees are not good in narrow area between curb and sidewalk, since roots of old plants will heave paving. Stake until good, basic branch pattern is established. Tolerant of acid or alkaline conditions, salt, drought, cold, heat, wind. Prune out any wayward or crossing branches. Susceptible to many pests, several of which are prevalent in humid-summer regions: mimosa webworm (chews leaves), pod gall midge (deforms foliage), honey locust borer (attacks limbs and trunks). Resist deer, however.
Popular garden selections include the following.
'Halka'. Fast growing; forms sturdy trunk early. Strong horizontal branching pattern; oval shape. To 4050 ft.
'Imperial'. Spreading, symmetrical tree to about 35 ft. More densely foliaged than other forms; gives heavier shade.
'Moraine'. Best-known selection. Fast-growing (to 50 ft. high), spreading tree with branches angled upward, then outward. Yellow fall color. Subject to wind breakage. Has greater resistance to webworms than do some of the newer selections.
'Rubylace'. Deep red new growth, fading to bronzed green by mid-summer. Subject to wind breakage, webworm attack.
'Shademaster'. More upright and faster growing than 'Moraine' to 24 ft. tall, 16 ft. wide in 6 years; eventually to 35 ft. tall, 25 ft. wide.
'Skyline'. Pyramidal and symmetrical, growing to 45 ft. tall. Bright golden fall color.
'Sunburst'. Golden yellow new leaves are showy against deep green background. Summer color is better in Upper and Middle South. Defoliates early in response to temperature changes, drought. Prone to wind breakage. Very susceptible to foliage pests. To 40 ft. tall.
'Trueshade'. To 40 ft. tall, with rounded form. Light green foliage.