The best time to plant sunflowers in South Carolina, which aligns with USDA zones 7a to 8b common in that area, is after the last frost has passed and soil temperatures are consistently above 50°F. This is typically around mid- April to early May for most parts of South Carolina. In warmer coastal regions, planting can start as early as March. Seedlings can also be started indoors 1-2 weeks before the last frost date. For continuous blooming, you can sow seeds every couple of weeks throughout the growing season from spring to early summer. Ensure the soil is well-drained and fertile for optimal growth.
In summary:
- Coastal and central South Carolina: planting as early as March is possible.
- Most other areas: late April to mid-May is ideal after frost risk is over.
- Seeds can be sown directly or started indoors shortly before transplant.
- To have blooms all summer, sow seeds every 10-14 days from May through August.
This timing helps sunflowers thrive with adequate warmth, sunlight, and frost protection.
