Japanese Pepper Tree
Zanthoxylum piperitum

Family: Rutaceae

What it is like

A deciduous shrub growing to about 15 feet, preferring a loamy soil but not really fussy as to soil or location. The ground-up seeds are used as a pepper substitute whilst the bark and leaves are used as a spice. The pulverized berries are the standard spice for sprinkling on broiled eel (kabayaki-unagi) and is one of the main ingredients of the blended spice called shichimi. A good forest garden plant. US Hardiness Zone: 5-9

Zanthoxylum piperitum is a deciduous Shrub growing to 2 m (6ft) by 2 m (6ft). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from April to June. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). . The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 2

Where it is found

Scrub and hedges in hills and mountains in Japan.

E. Asia - N. China, Japan, Korea.

Conservation Status:

Countries/locations it is found in

Asia, Australia, China*, India, Indochina, Indonesia, Japan*, Korea*, SE Asia, Taiwan, Tasmania, Thailand,

How it is used

Food

Rating: 3

Seed - cooked. It is ground into a powder and used as a condiment, a pepper substitute. The fruit can also be used. It is often heated in order to bring out its full flavour and can be mixed with salt for use as a table condiment. The ground and dry-roasted fruit is an ingredient of the Chinese 'five spice powder'. The bark and leaves are used as a spice. Young leaves - raw or cooked. They are used in soups or as a flavouring in salads.

Seed: includes nuts, cereals, peas and beans.

Condiment: the various plants that are used as flavourings, either as herbs, spices or condiments.

Medicine

Rating: 2

Antiperiodic, antitussive, carminative, diuretic, parasiticide, stimulant. The fruit contains a essential oil, flavonoids and isoquinoline alkaloids. It is anthelmintic, antibacterial, antifungal and stomachic. It inhibits the synthesis of prostaglandin and, in larger doses, is toxic to the central nervous system. It is used in Korea in the treatment of tuberculosis, dyspepsis and internal parasites. The resin contained in the bark, and especially in that of the roots, is powerfully stimulant and tonic.

Antibacterial: Kills bacteria.

Antifungal: An agent that inhibits or destroys fungi. Used in the treatment of various fungal problems such as candida.

Antiperiodic: Counteracts recurring illnesses such as malaria.

Antitussive: Prevents or relieves coughing.

Carminative: Reduces flatulence and expels gas from the intestines.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Parasiticide: Treats external parasites such as ringworm This should perhaps be joined with Parasiticide in

Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Stomachic: Aids and improves the action of the stomach.

Other

Rating: 1

In Japan, the thick wood of the tree is traditionally made into a gnarled and rough-hewn wooden pestle, to use with suribachi.

Parasiticide: Kills external body parasites such as hair lice.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

Scented Plants: Plants noted for their scent

How it is grown

Easily grown in loamy soils in most positions, but prefers a good deep well-drained moisture retentive soil in full sun or semi-shade. A very ornamental plant, it is hardy to about -15°c. Flowers are formed on the old wood. The bruised leaves are amongst the most powerfully aromatic of all leaves. Dioecious. Male and female plants must be grown if seed is required. Self-sown seedlings have occasionally been observed growing in bare soil under the parent plant. A good forest garden plant. Some reports suggest it can grow in deep shade. For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. A clumping plant, forming a colony from shoots away from the crown but with a limited spread. The root pattern is suckering with new plants from underground runners away from the plant.

Propagating it: Seed - best sown in a greenhouse as soon as it is ripe in the autumn. Stored seed may requires up to 3 months cold stratification, though scarification may also help. Sow stored seed in a cold frame as early in the year as possible. Germination should take place in late spring, though it might take another 12 months. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a cold frame for their first winter. Plant them out in early summer. Cuttings of half-ripe wood, July/August in a frame. Root cuttings, 3cm long, planted horizontally in pots in a greenhouse. Good percentage. Suckers, removed in late winter and planted into their permanent positions.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade;

Habit: Shrub

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Its other names

Local names

Anise pepper, Anise-pepper, Chin chiao, Chinese pepper, Chopinamu, Chop'inamu, Faah jiu, Fagara, Hu chiao, Hua chiao, Hua jiao, Japanese Prickly Ash, Japanischer Pfeffer, Pepper Ash, Poivre du Sechuan, Sansho, Szechwan pepper,

Synonyms

Fagara piperita.