Zanthoxylum simulans aka Chinese Pepper

Zanthoxylum simulans is known as Chinese pepper or Szechuan pepper. It belongs to the rue family, Rutaceae. Its native range includes China, South Korea and Taiwan. It grows in temperate regions, on hillsides and in open woods. This woody plant loses its leaves each year. It can form a bushy shrub or a small tree.

In gardens, it reaches about 8–13 feet [2.5–4 metres] tall and wide. The RHS gives this range for mature plants. NC State lists larger heights of 26–49 feet [7.9–14.9 metres]. Its crown can spread into a broad, flat top. Branches rise to form a vase shape. Growth proceeds at a medium rate. Plants may take 10–20 years to reach full size. Broad prickles grow on the trunk and branches. The bark is fairly smooth between these prickles. Its colours include dark grey and light brown.

The glossy green leaves grow in an alternate pattern. Each pinnate leaf has seven to eleven leaflets. Their shape recalls the leaves of an ash tree. The leaflets have toothed or rounded teeth along their edges. Crushed leaves release a scent, as do bark and fruit. Autumn foliage can turn red or burgundy. Small yellow-green flowers grow in flat clusters. Chicago records flowering in May and June. Other accounts place bloom in early summer or midsummer. Male and female flowers grow on separate plants. Female plants can make seeds and fruit without pollination. Red fruits split open to show black seeds. The fruit display and harvest fall in autumn.

Grow this plant in fertile soil that drains well. It accepts sun, partial shade or light shade beneath trees. Sources list sandy, loamy, clay and rocky soils as suitable. It also accepts acid, neutral and alkaline soil. Moisture can range from dry to moist. The RHS rates it H6 for cold hardiness. US sources give zones 5–9 or the narrower range 6–9. It suits borders, screens, woodland edges and small groups. It also serves as a specimen or security planting. NC State notes tolerance of wind and urban conditions.

Dried fruit segments provide a pungent spice for Chinese cooking. They form part of the five-spice blend. Light roasting brings out their flavour. The spice can cause a numbing feeling in the mouth. PFAF records traditional medicinal uses, including treatment of digestive complaints. RHS reports few pest or disease problems. Prickles remain a handling hazard. PFAF lists no known hazards, but RHS cautions against pets eating ornamental fruit.