Hardy Hibiscus — Growing reference
| Scientific name | Hibiscus moscheutos |
|---|---|
| Seed germination (days) | 14–21 |
| Soil temperature for germination (°C) | 21.1–29.4 |
| First harvest or flowering (days) | 90–120 |
| Measured from | Transplant |
| Plant spacing (cm) | 61–91.4 |
| Mature height (cm) | 91.4–182.9 |
| Mature spread (cm) | 61–121.9 |
| USDA hardiness zones | 4–9 |
| Light | Full sun |
| Water | High |
| Sowing method | indoor-start |
Growing directions
Nick or file seed coats and soak in warm water for 24 hours before sowing to improve germination rates significantly. Plant in full sun in moist, fertile soil — hardy hibiscus is native to wetlands and performs best with consistent moisture but tolerates average garden beds with regular irrigation. This is a late riser in spring; the shoots emerge much later than other perennials, so mark plants to avoid accidental disturbance. The dinner-plate-sized flowers in white, pink, and crimson open each morning and close by evening, with new blooms produced daily from midsummer through frost.
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