How to Grow Zanthoxylum simulans Plants in your Garden

Gardener's HQ Guide to Growing Flatspine prickly Ash / Chinese Pepper / Sichuan Pepper

Zanthoxylum simulans is a much loved plant in China as it is a source of Sichuan pepper. Although known as the Flatspine Prickly Ash in the West, it is more usually called the Chinese Pepper elsewhere.

It makes an easy to grow plant that can look good in a container, or in beds and borders.

Members of this genus are deciduous in nature and native to the mountains of China and East Asia.

Another member of this genus, Zanthoxylum piperitum, is also often used in the production of Sichuan pepper, but more correctly this plant is sanshō, the Japanese Pepper.

Zanthoxylum simulans
Chinese Pepper photograph by Plant Image Library, Creative Commons.

Although a tree that can reach about 22 feet (7 m) tall, Zanthoxylum simulans plants tend to take a shrub–like form, typically reaching 8 to 13 feet (2.5 to 4 m), with a similar spread.

Plants bloom in January in their native country, carrying tiny flowers of yellow-green that appear on cymes. These are followed by a reddish brown berry contains the black Sichuan pepper seeds.

Plants have a very strong peppery smell that is produced by the leaves, bark, and flowers. The leaves are a bright green, glossy and ovate shaped.

Flatspine prickly ash
Zanthoxylum simulans (Chinese Prickly-ash or Flatspine Prickly-ash) photograph by Kristine Paulus, CC.

As a member of the Zanthoxylum plant genus this plant is also closely related to Prickly Ash; Southern Prickly Ash; and Wild Lime.

Zanthoxylum simulans Growing and Care Guide

  • Scientific Name: Zanthoxylum simulans
  • Common Name: Flatspine prickly ash, Chinese Pepper, Chinese Prickly Ash, Sichuan pepper, Szechuan Pepper.
  • Growing Zone: USA: 5 to 8. UK hardiness H6 (Hardy to —20°C)
  • Life Cycle / Plant Type: Deciduous Tree or large Shrub. Bushy habit.
  • Best Garden Use: Beds, Border, En masse, Containers, Patio, Low maintenance gardens.

Plant Details

  • Plant Height : 8 to 22 feet (2.5 to 7 m)
  • Plant Spread (Inches): 8 to 22 feet (2.5 to 7 m)
  • Time of Bloom: Mid-winter.
  • Flower Details: Tiny. Clusters. White, Yellow-Green.
  • Leaf Foliage: Small, Ovate and Ash-like, Bright Green, Glossy. 3 inches (8 cm) long.
  • Fragrance: Aromatic Leaves, Fruit, and bark. Peppery, Sweet, Myrcene.
  • Fruit: Berry, Red-brown, contains black pepper seeds.
  • Growth Form: Rounded to upright

Ideal Growing Conditions

  • Best Light Conditions: Partial / Dappled shade to full sunlight (best results in full sun).
  • Rate of Growth: Medium paced
  • Suitable Soil Types: light to heavy (Sandy, Loam, Clay) soils of most soil pH acidities.
  • Soil Moisture: Moist, and Well drained

Zanthoxylum Care Conditions

  • Level of Maintenance: Low to Medium
  • Propagation:
    Seed. Sow ripe seed in autumn. Older seed should be sown outdoors at the beginning of January in a cold frame to allow them to stratify. Seeds should germinate in the frost or second spring.
    Softwood Cuttings: Mid to late summer. Root in a frame with bottom heat.
    Root Cuttings: Greenhouse. About 1 inch in length (3 cm). Horizontal. Containers.
  • How to Prune: Light pruning to remove diseased, congested or dead tissues in late winter.
  • Further Care Details: Grow in sheltered location. Provide mulch and feed following pruning.

Further Information

  • Can Attract:
  • Tolerant of:
  • Miscellaneous: Genus named after the Latin for yellow Wood'. Inconspicuous flowers or blooms, Periodic blooms. Great Bonsai tree.
  • Genus Detail: Zanthoxylum

I hope that you enjoyed this guide on how to grow Zanthoxylum simulans. You may also enjoy the following growing guides on plants that can be used for Bonsei: How to grow Camellia japonica and Wisteria Plant.