- native to parts of the central Untied States
- hardy to zone 4
Habit and Form
- a medium to large deciduous tree
- 50' to 60' tall
- spread is usually equal to height
- branching is upright-spreading to arching or more or less horizontal
- some trees become nearly flat-topped
- rather loose and open
- casts only light shade
- develops a short main trunk
- alternate, pinnately or bipinnately compound leaves
- typically with many small leaflets
- leaves are 6" to 8" long
- bright green glossy leaves
- late to leaf out in spring
- leaves turn a showy, clear yellow
- leaves typically drop early
- small, greenish-yellow flowers
- blooms in May and June
- blossoms are fragrant
- do not constitute a major ornamental feature
- 7" to 18" long, twisted, flattened pods
- approximately 1" wide
- changes from green to dark brown
- some cultivars are fruitless
- fruits can be numerous and messy
- gray-brown color
- develops elongated, smooth, plate-like patches separated by furrows
- rather attractive
- stems and even main trunk can have large, branched thorns present
- full sun
- adaptable to a range of soils
- grows best in deep, moist, fertile soils of neutral pH
- probably performs best in soils that are not too acidic
- tolerant of pollution
- tolerant of salt
- lawn tree
- street tree where space permits
- useful for light shade it cast, which permits turf to grow beneath
- use maybe should be tempered in light of past overuse and urban monoculture of honeylocust
- large thorns can be dangerous
- pods can be messy
- spider mites
- mimosa webworm
- pod gall midge
- pinnate and bipinnately compound leaves
- upright-spreading, arching or horizontal branching
- short main trunk
- large thorns on trunk and branches
- large flat, twisted pods
- by seed
- cultivars are bud grafted
Nearly all forms in cultivation today are selections of the naturally-occuring variety inermis (also listed as v. inermis or var. inermis). These plants do not produce thorns of their stems, though fruit (leguminous pods) may be seen. The following selections are derived from G. t. var. inermis, unless noted.
'Christie' (Halka) - This sturdy-trunked form is known for its round-headed crown with less drooping branches. It will reach 40' tall and wide and rarely fruits.
'Impcole' (Imperial®) - Unusual for its relatively dwarf mature size, this 35' tall tree has a compact spreading habit. It produces few pods and has very fine-textured foliage that turns yellow in fall.
'Moraine' - This selection was the earliest thornless form to be patented (in 1949) and widely introduced on the market. It is fruitless and forms a wide, spreading tree 40' tall and wider. Good pest resistance and yellow fall color ensure this plant's continued popularity.
'Shademaster' (Shademaster®) - This form is popular for its upright, symmetrical growth habit to 40' tall. It produces some pods and has good, deep green foliage. It also reportedly has very good drought tolerance.
'Skycole' (Skyline®) - A cold-hardy form with yellow fall color and few fruits, this selection is most notable for its unusual upright growth habit. It forms a broadly pyramidal tree 40' tall and wide. It makes a good street tree and is widely regarded as one of the finest forms available.
'Speczam' (Spectrum) - Early spring bright yellow foliage is the main feature of this new form, which purportedly holds its golden hue later into the season than other gold-foliaged forms. The habit is rounded and 35' tall and wide.
'Suncole' (Sunburst®) - This a very popular tree noted for the new foliage, which emerges with a bright gold hue before fading to green. The plant reaches 35' tall and has an irregular habit with non-symmetrical branching. It is fruitless but supposedly susceptible to a canker disease. Ideally it should be used in moderation, as mass plantings of the bright yellow foliage can be unpleasant.