How to Grow Toothache Plant
Acmella oleracea
Toothache Plant is a tender tropical herb grown for its distinctive yellow-and-red eyeball-like flower heads that cause a strong tingling, numbing sensation when chewed. Start seed indoors 6 weeks before last frost, surface-sowing on warm, moist compost at 20–25°C. Plant out only once nights are reliably above 15°C. Grow in full sun with consistently moist but well-drained soil; waterlogging causes root rot. Pinch tips regularly for bushy growth. Harvest flower heads and young leaves freely — the more you pick, the more it flowers. Both leaves and flowers are edible in salads, cocktails, and as a culinary novelty. Frost kills it immediately, so bring cuttings indoors before temperatures drop.
In your Leaftide garden - Hardiness
- Tender
- Season
- Warm Season
- Harvest
- Continuous Harvest
- Spacing
- 30 cm
- Height
- 40 cm
- Min. soil temperature
- 18°C+
- Start from
- Seed
- Light
- Full sun to part shade
- Water
- High
When to Start
Start seeds indoors 6 weeks before your last frost date. Transplant outdoors once night temperatures stay above 15°C and soil has warmed to at least 18°C.
Don't know your frost date? Find it here →
Growth Stages
Approximate days from start
Care Essentials
- Light liquid feed every 3 weeks. Avoid high-nitrogen feeds — they reduce flowering.
- Needs warmth — minimum 15°C. Keep soil consistently moist but never waterlogged. Excellent companion plant and culinary curiosity; the electric tingling sensation is due to spilanthol.
Growing Conditions
- Min. soil temperature
- 18°C+
- Germination temperature
- 20–25°C
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
Want your full season plan with reminders? Set up your garden free
Spacing & Planting
| Plant spacing | 30 cm |
| Row spacing | 45 cm |
| Sow depth | 0 cm |
| Mature height | 40 cm |
| Mature spread | 30 cm |
Growing Conditions
| Min. soil temperature | 18°C |
| Germination temperature | 20–25°C |
| Base growth temperature | 15°C |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Toothache Plant?
- Plant Toothache Plant 30cm apart with 45cm between rows.
- When can I harvest Toothache Plant?
- Toothache Plant is ready to harvest approximately 65 days after transplanting.
- Is Toothache Plant frost hardy?
- Toothache Plant is classified as Tender.