How to Grow Four O'Clock Flower
Mirabilis jalapa
Four O'Clocks are fast-growing tuberous perennials grown as half-hardy annuals in cooler climates. Sow seeds indoors in spring or direct sow after last frost. They thrive in full sun to partial shade in any well-drained soil. Plants form bushy mounds 60-90cm tall and wide, producing fragrant trumpet-shaped flowers that open in late afternoon. Deadhead regularly and feed fortnightly. In cold areas, lift tubers after first frost and store dry over winter.
When to Start
Sow indoors 6 weeks before last frost, or direct sow outdoors after frost risk has passed and soil reaches 15°C.
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Growth Stages
Approximate days from start
Care Essentials
- Liquid feed every two weeks during the growing season to encourage flowering.
- A fast-growing, self-seeding plant. Flowers open in late afternoon and are fragrant in the evening. Tubers can be lifted and stored like dahlias in cold climates.
Growing Conditions
- Min. soil temperature
- 15°C+
- Germination temperature
- 18–24°C
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
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Spacing & Planting
| Plant spacing | 45 cm |
| Row spacing | 60 cm |
| Sow depth | 1 cm |
| Mature height | 80 cm |
| Mature spread | 60 cm |
Growing Conditions
| Min. soil temperature | 15°C |
| Germination temperature | 18–24°C |
| Base growth temperature | 10°C |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Four O'Clock Flower?
- Plant Four O'Clock Flower 45cm apart with 60cm between rows.
- When does Four O'Clock Flower flower?
- Four O'Clock Flower typically flowers approximately 60 days after transplanting.
- Is Four O'Clock Flower frost hardy?
- Four O'Clock Flower is classified as Half Hardy.
