Four O'Clock — Growing reference
| Scientific name | Mirabilis jalapa |
|---|---|
| Seed germination (days) | 7–14 |
| Soil temperature for germination (°C) | 18.3–23.9 |
| First harvest or flowering (days) | 60–90 |
| Measured from | Seed |
| Plant spacing (cm) | 45.7–61 |
| Mature height (cm) | 61–121.9 |
| Mature spread (cm) | 45.7–91.4 |
| USDA hardiness zones | 7–11 |
| Light | Partial sun |
| Water | Low |
| Sowing method | Direct sow |
Growing directions
Sow seeds or plant tubers in well-drained soil in full sun to partial shade; four o'clock is a vigorous, heat-loving, tuberous perennial native to tropical America that has been grown in gardens worldwide since the 16th century. The trumpet-shaped flowers in red, yellow, pink, white, or bicolor (sometimes more than one color on the same plant) open in the late afternoon (hence the name) and stay open through the night, closing in morning — making them essential for moths and evening pollinators including sphinx moths, which are their primary pollinators. The fragrance intensifies in the evening. Established tubers in zone 7–11 can grow to grapefruit size and resprout from deeper in the soil each year, often becoming permanent garden residents. In zone 9a they naturalize and can self-sow vigorously — seedlings are easy to remove if unwanted.
Source and local conditions
Typical planning ranges from OpenPlantDB (CC0). Cultivar, climate, season and growing method can change these values. Confirm the seed label and local guidance before planting.
Source & verification
OpenPlantDB · CC0