When to Plant Onion in Iredell 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.
Iredell County, North Carolina is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is November 1, giving you a growing season of approximately 208 days.
At an elevation of 400 feet, Iredell County receives approximately 44.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, providing good warmth for Onion during the growing season. Clay soil retains moisture well for Onion, but amend with compost to improve drainage and prevent root rot.
Iredell County Soil Profile
Soil Type
Clay Loam
Soil pH
5.5-6.7
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 — Iredell County, NC
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Direct Sow | March 24 | Mar 24 – Apr 14 |
| Fall Sowing | August 23 | Aug 23 – Sep 6 |
| Harvest | July 7 | Jul 7 – Aug 25 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| 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 7b
Growing Season
208 days
Growing Tips for Iredell 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 Iredell County, NC?
Iredell County is in Zone 7b with an average last frost of April 7. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Iredell County, NC?
Iredell County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is November 1.
Plan Your Garden with Confidence
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