common prickly-ash

Photo: A. Barra — CC BY-SA 4.0 · source

Survives zone 3 through 7

Harvest calendar

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

Citrus as familiar. ⚠ Zanthoxylum = a numbing SPICE (husks), not a fruit. Clove-scented spice drupes.

Hardiness

Zone 3–7

Habit

Shrub

Edible part

Fruit

Ripens

Winter (citrus)

Mature size

Suckering shrub or small tree 3–8 m, thicket-forming

Light

Full sun to partial (understory-capable)

Soil pH

6.0–6.5 (slightly acid)

Environment

Temperate

Native range

Eastern and central North America — Quebec and Ontario south to Georgia, west to North Dakota and Oklahoma; woodland edges, thickets and rocky slopes.

Status

Wild

Years to fruit

2–3 yrs

Growth speed

20–40 cm/year — medium.

Spacing

300 cm (118 in) apart — about 9 m² (97 sq ft) per plant

Leaf shape

Alternate and pinnate with 5–11 oval leaflets, downy when young and strongly citrus-scented when crushed, with stout paired prickles at each node.

Root system

Shallow and strongly suckering, throwing root shoots that build a thorny thicket over time — useful for a stock-proof hedge, awkward in a border.

Fruit description

Small reddish-brown follicles about 4–5 mm across in tight clusters along the stems, splitting to reveal a glossy black seed; the husk is aromatic and numbing like true Sichuan pepper, and the tingling it causes gave the plant its old name of toothache tree.

Propagation

Seed germinates poorly once dried, so sow fresh in autumn, or give 2–3 months cold stratification. Semi-ripe cuttings in midsummer with bottom heat, or root cuttings taken in late winter, are both quicker and keep a known sex.

Pollination

⚠ Dioecious — male and female flowers on separate plants, so an isolated shrub will never fruit. It suckers into single-sex thickets, which is why a large wild stand can bear nothing at all. 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.