Spilanthes (Toothache plant)

Acmella oleracea

Sprawling tropical perennial with curious red-and-yellow button flower heads. Chewing the flower head produces a strong tingling, numbing sensation — a topical local anaesthetic.

Hardiness ratings

Spilanthes (Toothache plant) hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 9–11 −6.7 °C to 10 °C Zones where it can be grown as an annual — not a frost-tolerance rating
RHS hardiness rating H3 −5 °C to 1 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 9 −1 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating
Australian (ANBG) zone Zone 5–7 5 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating

As a tender annual, Spilanthes (Toothache plant) doesn't overwinter — the zone range shows where the growing season supports it. See the RHS rating for its actual cold tolerance.

Growing notes

  • Perennial in zone 9+, grown as annual elsewhere
  • Children find the chewing sensation either delightful or alarming — supervise first try
  • Always consult a qualified medical or herbal practitioner before using any plant medicinally

Categories

Related plants

Cross-check Spilanthes (Toothache plant) against your zones

Reference

Spilanthes (Toothache plant) on Wikipedia