Acmella oleracea is a herbaceous perennial native to South America, commonly known as toothache plant due to its anesthetic properties from the compound spilanthol. Seeds require light to germinate and should be surface-sown on moist, well-drained seed compost without covering.
Before sowing
No pre-treatment needed — sow directly.
Sowing
What to expect
Tips
Keep seed trays moist but not wet. High humidity promotes germination. Seeds are very small (4545 seeds per gram). Start seeds indoors in frost-free conditions in spring. Transplant seedlings when large enough to handle. Plant prefers warm, sunny locations with moist, well-drained soil.
Sources: Johnny's Seeds, Floral Encounters, GrowPlants, Plant Flower Seeds, Plantiary, Chiltern Seeds, The Seed Collection, SciELO Brazil (morphology and germination study), RHS, Wikipedia
