honey locust

Photo: Plant Image Library from Boston, USA — CC BY-SA 2.0 · source

Survives zone 4 through 9

Harvest calendar

Best planted in early spring after your last frost, or in fall before the ground freezes, depending on your climate.

The crop is the sweet sticky pulp inside the long pods — chewed straight from the pod, or used to sweeten and flavour drinks. The hard seeds are not eaten. ⚠ Do not confuse this with Kentucky coffeetree (Gymnocladus dioicus), whose raw seeds are toxic. The wild type is savagely thorny; buy a named thornless form for a garden.

Hardiness

Zone 4–9

Habit

Tree

Edible part

Fruit

Ripens

Autumn

Mature size

Large tree 20–30 m — not containerable

Light

Full sun

Soil pH

6.0–7.5; tolerates poor, compacted, dry and mildly saline soil

Environment

Temperate

Native range

Central and eastern North America, from Pennsylvania west to Nebraska and south to Texas — river bottoms, floodplains and limestone woods. Planted worldwide since, and invasive in Australia, Argentina and parts of South Africa.

Status

Both wild and cultivated

Years to fruit

3–5 yrs

Growth speed

Fast — 60 cm or more a year when young

Spacing

1000 cm (394 in) apart — about 100 m² (1076 sq ft) per plant

Leaf shape

Alternate, pinnate or bipinnate on the same tree, 15–20 cm, with many small oval leaflets that cast a famously light dappled shade and need no raking in autumn. ⚠ The wild type carries branched thorns up to 20 cm on trunk and limbs; thornless forms are the ones sold for gardens.

Root system

A deep taproot early, then wide, coarse, aggressive laterals that sucker where they are damaged. ⚠ Despite being a legume, honey locust forms no root nodules at all — it is one of the non-nodulating legumes, so do not plant it expecting to feed its neighbours the way an alder or a Siberian pea shrub does.

Fruit description

Long flat twisted pods 15–40 cm, ripening dark red-brown and staying on the tree into winter. ⚠ The crop is the sweet sticky pulp between the seeds, which is edible and was used for beer and sweetening; the hard seeds themselves are not eaten, and the closely related Kentucky coffeetree's seeds are toxic — do not confuse the two.

Propagation

Seed after scarification (nick or hot-water soak) — germination is easy and quick. Named thornless clones must be grafted or budded, since seedlings revert to thorns.

Pollination

Polygamo-dioecious — plant more than one tree for reliable pods; insect-pollinated

The edible parts listed above are a starting point, not a field guide. Identify a plant with certainty — ideally against a local authority — before eating any part of it, and read the full disclaimer. Spotted something wrong? Report it.