When to plant onion (bulbing)
Onion (bulbing) timing, counted from your average last spring frost and first fall frost. Pick day-length type for latitude: short-day in the South (planted fall/winter), long-day in the North. Sets/transplants go in about 4–6 weeks before last frost.
| Season | cool-season, hardy to frost |
|---|---|
| Start indoors | 12 weeks before to 10 weeks before the last frost |
| Transplant | 6 weeks before to 4 weeks before the last frost |
| Soil temperature to germinate | 35°F or warmer |
| Days to maturity | 90–120 days from transplant |
| Spacing | 4–6 in apart, rows 12–18 in apart |
| Seed depth | 0.5 in |
Example dates
| Place | Dates |
|---|---|
| Austin, TX (78701) | Start seeds indoors: Dec 16–30; Transplant: Jan 27–Feb 10 |
| Atlanta, GA (30303) | Start seeds indoors: Dec 30–Jan 13; Transplant: Feb 10–24 |
| St. Louis, MO (63101) | Start seeds indoors: Jan 7–21; Transplant: Feb 18–Mar 4 |
| Chicago, IL (60614) | Start seeds indoors: Jan 16–30; Transplant: Feb 27–Mar 13 |
| Denver, CO (80202) | Start seeds indoors: Feb 5–19; Transplant: Mar 19–Apr 2 |
| Seattle, WA (98101) | Start seeds indoors: Dec 19–Jan 2; Transplant: Jan 30–Feb 13 |
Every ZIP page has its own dates. Find your ZIP.
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Sources
- University of Missouri Extension: G6201: Vegetable Planting Calendar
- K-State Research and Extension: MF315: Vegetable Garden Planting Guide
- University of Maryland Extension: When to Plant Vegetables
- NC State Extension: Central North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs
- UF/IFAS Extension (EDIS): SP 103/VH021: Florida Vegetable Gardening Guide
- Clemson Cooperative Extension HGIC: Planning a Garden
Summarized in our own words from public extension publications.
All vegetables · Your ZIP's planting calendar
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