How to Grow Phacelia
Phacelia tanacetifolia
Phacelia is a fast-growing hardy annual with a dual role — a spectacular bee-magnet flower and one of the best green manures. Sow direct where it is to grow from spring to early autumn. It flowers within 6-8 weeks, producing masses of lavender-blue curled flower heads that bees adore. As green manure, chop and dig in before or just after flowering to add organic matter and improve soil structure. No feeding or fuss needed — just scatter seed and let it grow.
When to Start
Direct sow outdoors as soon as soil reaches 8°C — typically early to mid spring. Hardy enough to tolerate light frosts.
Don't know your frost date? Find it here →
Growth Stages
Approximate days from start
Care Essentials
- No feeding needed. Phacelia thrives in poor to average soil and actually performs its green manure function best without added fertility.
- Phacelia is a fast-growing hardy annual with dual purpose — a stunning bee-magnet flower and an excellent green manure. It germinates quickly, grows fast, and flowers within 6-8 weeks of sowing. As green manure, it builds organic matter, suppresses weeds, and its fine roots improve soil structure. Bees are intensely attracted to the lavender-blue flowers. Can be sown spring through early autumn.
Growing Conditions
- Min. soil temperature
- 8°C+
- Germination temperature
- 10–25°C
- Direct sow
- —
- First harvest
- —
Want your full season plan with reminders? Try Leaftide free
Spacing & Planting
| Plant spacing | 20 cm |
| Row spacing | 30 cm |
| Sow depth | 0.5 cm |
| Mature height | 60 cm |
| Mature spread | 30 cm |
Space 20 cm apart or broadcast seed thinly for green manure use. For ornamental borders, thin to 20 cm for best display.
Growing Conditions
| Min. soil temperature | 8°C |
| Germination temperature | 10–25°C |
| Base growth temperature | 5°C |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Phacelia?
- Plant Phacelia 20cm apart with 30cm between rows.
- When does Phacelia flower?
- Phacelia typically flowers approximately 55 days after transplanting.
- Is Phacelia frost hardy?
- Phacelia is classified as Hardy.
