Climate matters. This page is a practical baseline. Confirm cultivar, local frost/heat conditions, mature size and regional restrictions before planting.
Coreopsis — Growing reference
| Scientific name | Coreopsis grandiflora |
|---|---|
| Seed germination (days) | 14–21 |
| Soil temperature for germination (°C) | 15.6–21.1 |
| First harvest or flowering (days) | 70–120 |
| Measured from | Seed |
| Plant spacing (cm) | 30.5–45.7 |
| Mature height (cm) | 45.7–91.4 |
| Mature spread (cm) | 45.7–61 |
| USDA hardiness zones | 4–9 |
| Light | Full sun |
| Water | Low |
| Sowing method | Direct sow |
Growing directions
Sow seed on the soil surface and tamp lightly; good drainage is essential since coreopsis rots in wet soil over winter. Deadhead regularly to keep the bright yellow flowers coming all summer. Shear plants back by half after the first flush to encourage compact regrowth and a second bloom. Divide clumps every 2–3 years in spring to prevent the center from dying out.
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