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How to Grow Zanthoxylum clava-herculis Plants in your Garden

Hercules club

Hercules' Club leaves photograph by Homer Edward Price.

Gardener's HQ Guide to Growing Hercules Club and Southern Prickly Ash

Zanthoxylum Clava Herculis is a small deciduous tree or large shrub that is native to the coastal plains of South-eastern parts of the USA.

Despite being a Citrus, this plant is often referred to as the Southern prickly ash. This is because it looks like a prickly version of the Southern Ash tree.

It can look great as a hedging or screening plant, or use it as a specimen tree, with the added advantage that it is able to attract the Giant Swallowtail butterfly to the garden.

Zanthoxylum Clava Herculis Description

Hercules' club has a rounded form and often grows in thickets and is known for its spiny grey bark. Although it can reach as high as 17 m (50 feet) it usually grows to a much smaller height, and often looks more like a small shrub than a tree.

It has leathery compound leaves of green. While the flowers are yellow, typically blooming from early to mid-summer. The bark, flowers, and leaves are all aromatic.

Zanthoxylum Clava Herculis Traditional Uses and Facts

The plant is also known by the names of Tingle Tongue and Toothache tree. This is because the twigs, bark, and leaves will cause the mouth and gums to tingle and go numb, and hence repress toothache.

Because of this both the indigenous people and the early settlers to the south eastern parts of the USA used the tree as a cure, be it temporally, for toothache and mouth issues such as ulcers.

Zanthoxylum clava herculis

Print of Zanthoxylum clava herculis and a Ground Dove sourced by the Biodiversity Heritage Library, creative commons.

The roots and bark are rich in the aromatic oil xanthoxylin. Tinctures made from the bark have traditionally been used to support rheumatism, itchy skin, and cardiac issues.

The genus Zanthoxylum gets its name from the Greek words for yellow (xanthos) and wood (xylon). While the remainder of the species name – Zanthoxylum – refers to the club-shaped nature of the plant and to the Greek hero Hercules, who swinged a club-shaped weapon.

Zanthoxylum clava-herculis Growing and Care Guide

  • Scientific Name: Zanthoxylum clava-herculis
  • Common Name: Hercules club, Southern Prickly Ash, Pepperwood, Pepperbark, Toothache Tree, Tickle Tongue.
  • Growing Zone : USA: 7 to 9. UK H6 (Hardy to -20°C (-4°F)
  • Life Cycle / Plant Type: Tree, shrub

Plant Details

  • Plant Height: 15 to 50 feet (4.5 to 15 m)
  • Plant Spread (Inches): 15 to 30 feet (4.5 to 9 m)
  • Time of Bloom: Late spring and Early Summer
  • Flower Details: Yellow, white
  • Leaf Foliage: Green. Leathery. Pinnate. 8 to 12 inches in length (20 to 30 cm).
  • Fruit: Capsule. Two valves. Small Black seeds.
  • Fruit:
  • Growth Form: Rounded

Ideal Growing Conditions

  • Best Light Conditions: Partial shady to full sunlight
  • Rate of Growth: Medium paced.
  • Suitable Soil Types: Deep, Sandy, Well drained.
  • Soil Moisture: Moist

Care Conditions

  • Level of Maintenance: Low to Medium.
  • Sowing and Propagation:
    SeedStratify seed for three months. Or sow fresh seed indoors in the autumn. Germinates in the next or the following spring. Transfer seedlings to a cold frame in individual pots. Transplant to final location in early summer.
    Propagate Semi-ripe cuttings in summer (cold-frame). Roots: Greenhouse. Cut roots to 1 1/4 inch (3 cm) lengths. lay in pots in a horizontal position.

Further Information

  • Can Attract: Butterflies, Beetles
  • Tolerant of: Poor soil
  • Best Garden Use: Hedge, Border, En masse, Butterfly gardens. Attracts birds and deer.
  • Family:
  • Closely Related Species:
  • Miscellaneous: North American Native, Attracts butterflies, Inconspicuous flowers or blooms. Genus also known as Xanthoxylum. Referred to as the toothache tree because of the numbing sensation caused through chewing their leaves.
  • Family: Rutaceae, the Citrus and Rue family
  • Further Reading and References: Here and Plants for a future
  • Family: Rutaceae (Citrus / Rue Family)
  • Closely Related Species: Wild Lime; Chinese Pepper; and Prickly Ash