When to Plant Onion in Guilford 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.
Guilford County, North Carolina is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 30, giving you a growing season of approximately 207 days.
At an elevation of 579 feet, Guilford County receives approximately 45.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°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.
Guilford County Soil Profile
Soil Type
Clay Loam
Soil pH
5.6-6.4
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 — Guilford County, NC
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 23 | Mar 23 – Apr 13 |
| Fall Sowing | August 21 | Aug 21 – Sep 4 |
| Harvest | July 6 | Jul 6 – Aug 24 |
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
207 days
Growing Tips for Guilford 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 Guilford County, NC?
Guilford County is in Zone 7b with an average last frost of April 6. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Guilford County, NC?
Guilford County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 30.
Plan Your Garden with Confidence
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