Japanese pepper (sanshō) Zanthoxylum piperitum
Japanese pepper (sanshō) (Zanthoxylum piperitum) is a deciduous perennial shrub in the Rutaceae family, native to Japan and southern Korea. It grows 1.5–3 m (4.9–10 ft) tall and 1–2 m (3.3–6.6 ft) wide, wants part sun to part shade and moderate water, and is hardy to about -18 °C (0 °F). Space plants about 1.5 m (4.9 ft) apart.
Plan Japanese pepper (sanshō) in your garden →
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Japanese pepper (sanshō) at a glance
| Type | Perennial shrub, deciduous |
|---|---|
| Family | Rutaceae |
| Mature height | 1.5–3 m (4.9–10 ft) |
| Mature spread | 1–2 m (3.3–6.6 ft) |
| Spacing | 1.5 m (4.9 ft) centre to centre |
| Sun | Part sun to part shade, at least 4 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance none |
| Soil pH | 5.5–7 |
| Cold hardiness | About -18 °C (0 °F) once established (roughly USDA zone 6) |
| Heat stress | Likely above about 34 °C (93 °F) |
| Flowering | from about April for 1–3 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Yes: young leaves (kinome), ground fruit husks (sanshō pepper) |
| Native to | Japan and southern Korea |
| Common in gardens of | 🇯🇵 Japan, 🇰🇷 South Korea, 🇨🇳 China |
Is Japanese pepper (sanshō) toxic?
- People: not known to be toxic
- Cats: mildly toxic
- Dogs: mildly toxic
- Parts: thorns
Paired prickles on stems.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Japanese pepper (sanshō)
No well-documented helpful pairing. Group it with plants that like part sun to part shade and moderate water.
Keep apart or take care
- caution With Sweet orange: Asian citrus psyllid spreads huanglongbing (citrus greening) between citrus and relatives such as orange jasmine (Murraya). Keep new citrus away from infected or neglected hosts. Evidence B
Questions about Japanese pepper (sanshō)
- How far apart should I plant Japanese pepper (sanshō)?
- About 1.5 m (4.9 ft) apart, centre to centre. A mature plant spreads 1–2 m (3.3–6.6 ft).
- Does Japanese pepper (sanshō) need full sun?
- Part sun to part shade: at least 4 hours of direct sun a day.
- How much water does Japanese pepper (sanshō) need?
- Moderate water. Drought tolerance is low and waterlogging tolerance none.
- How cold-hardy is Japanese pepper (sanshō)?
- It tolerates about -18 °C (0 °F) once established, roughly USDA zone 6.
- When does Japanese pepper (sanshō) flower?
- From about April for 1–3 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Japanese pepper (sanshō) poisonous to cats and dogs?
- For cats it is mildly toxic; for dogs mildly toxic; for people not known to be toxic. Paired prickles on stems.
- What grows well with Japanese pepper (sanshō)?
- There is no well-documented companion pairing for Japanese pepper (sanshō). Group it with plants that like the same sun (part sun to part shade) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Plants For A Future database, PFAF
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
Notes and assumptions
- A Sichuan-pepper relative with a numbing citrus tingle; dust on grilled eel. Male and female plants.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
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- Curry tree Murraya koenigii
- Kaffir lime Citrus hystrix
- Common rue Ruta graveolens
- Sweet orange Citrus x sinensis
- Mandarin orange Citrus reticulata
- Persian lime Citrus x latifolia
- Key lime Citrus x aurantiifolia