When to Plant Onion in Horry County, SC
Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.
Horry County, South Carolina is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 10, giving you a growing season of approximately 232 days.
At an elevation of 439 feet, Horry County receives approximately 53.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Onion during the growing season. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.
Horry County Soil Profile
Soil Type
Sandy Loam
Soil pH
4.9-5.9
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Onion Planting Timeline — Horry County, SC
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 16 | Feb 16 – Mar 2 |
| Transplant Outdoors | March 23 | Mar 23 – Apr 6 |
| Direct Sow | March 9 | Mar 9 – Mar 30 |
| Fall Sowing | September 1 | Sep 1 – Sep 15 |
| Harvest | June 22 | Jun 22 – Aug 10 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
6 – 7
USDA Zone
Zone 8a
Growing Season
232 days
Growing Tips for Horry County
Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Horry County, SC?
Horry County is in Zone 8a with an average last frost of March 23. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Horry County, SC?
Horry County, South Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 10.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Horry County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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