How to Grow Blue Butterfly Pea
Clitoria ternatea
Blue Butterfly Pea is a heat-loving tropical climber grown as an annual in temperate gardens. Start seeds indoors 5 weeks before the last frost, soaking them overnight to aid germination. Plant out after all frost risk has passed into warm, well-drained soil in full sun, and provide a trellis or support immediately — it climbs fast. Water moderately and feed lightly; too much nitrogen reduces flowering. The vivid blue flowers appear continuously from midsummer and are edible, used to make striking blue tea and natural food colouring. Pick flowers regularly to keep them coming.
When to Start
Start seeds indoors 5 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 balanced feed monthly during the growing season. Avoid high nitrogen which encourages leafy growth at the expense of flowers.
- A fast-growing climber that thrives in heat and sun. Provide a trellis or support from planting. The vivid blue flowers make excellent natural food colouring — the pigment turns purple with acid and green with alkali.
Growing Conditions
- Min. soil temperature
- 18°C+
- Germination temperature
- 20–30°C
Enter your last frost date to see your dates
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
Want your full season plan with reminders? Try Leaftide free
Spacing & Planting
| Plant spacing | 30 cm |
| Row spacing | 45 cm |
| Sow depth | 1 cm |
| Mature height | 250 cm |
| Mature spread | 50 cm |
Growing Conditions
| Min. soil temperature | 18°C |
| Germination temperature | 20–30°C |
| Base growth temperature | 15°C |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Blue Butterfly Pea?
- Plant Blue Butterfly Pea 30cm apart with 45cm between rows.
- When does Blue Butterfly Pea flower?
- Blue Butterfly Pea typically flowers approximately 70 days after transplanting.
- Is Blue Butterfly Pea frost hardy?
- Blue Butterfly Pea is classified as Tender.
