When to Plant Onion in Robeson County, NC
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.
Robeson County, North Carolina is in USDA Zone 8a. The average last spring frost is March 24 and the first fall frost is November 6, giving you a growing season of approximately 227 days.
At an elevation of 887 feet, Robeson County receives approximately 49.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97°F, so Onion may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Onion, but amend with compost to improve drainage and prevent root rot.
Robeson County Soil Profile
Soil Type
Clay Loam
Soil pH
5.3-6.2
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Onion Planting Timeline — Robeson County, NC
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 17 | Feb 17 – Mar 3 |
| Transplant Outdoors | March 24 | Mar 24 – Apr 7 |
| Direct Sow | March 10 | Mar 10 – Mar 31 |
| Fall Sowing | August 28 | Aug 28 – Sep 11 |
| Harvest | June 23 | Jun 23 – Aug 11 |
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 | Fall Sowing 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
227 days
Growing Tips for Robeson 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 Robeson County, NC?
Robeson County is in Zone 8a with an average last frost of March 24. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Robeson County, NC?
Robeson County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 24 and first fall frost is November 6.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Robeson County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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