When to Plant Onion in Zone 10
Allium cepa
Last updated: Apr 25, 2026 · Sources: USDA, NOAA, Cooperative ExtensionZone 10 Planting Schedule
Start Indoors
Jan 13
6–8 weeks before transplant
Transplant Out
Feb 10
After last frost (Feb 10)
Direct Sow
Feb 10
Directly in garden bed
First Harvest
May 21
90–120 days after planting
Season Ends
Jul 20
Before first frost (Dec 10)
Quick Facts
Sunlight
☀️ Full Sun
Water Needs
💧💧 Moderate
Spacing
6 inches apart
Planting Depth
1.0 inch
Min Soil Temp
35°F
Germination
7–14 days
Days to Maturity
90–120 days
Frost Tolerance
Heavy frost tolerance
Soil pH
6.0–7.0
Difficulty
Moderate
Recommended for Zone 10
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Beans Peas
Onion Schedule — All Zones
| Zone | Start Indoors | Transplant | Direct Sow | Harvest Start | Harvest End |
|---|---|---|---|---|---|
| Zone 3 | Apr 17 | May 15 | May 15 | Aug 23 | Sep 12 |
| Zone 4 | Apr 12 | May 10 | May 10 | Aug 18 | Sep 22 |
| Zone 5 | Apr 2 | Apr 30 | Apr 30 | Aug 8 | Oct 2 |
| Zone 6 | Mar 18 | Apr 15 | Apr 15 | Jul 24 | Sep 22 |
| Zone 7 | Mar 8 | Apr 5 | Apr 5 | Jul 14 | Sep 12 |
| Zone 8 | Feb 20 | Mar 20 | Mar 20 | Jun 28 | Aug 27 |
| Zone 9 | Jan 31 | Feb 28 | Feb 28 | Jun 8 | Aug 7 |
| Zone 10 | Jan 13 | Feb 10 | Feb 10 | May 21 | Jul 20 |
| Zone 11 | Jan 1 | Jan 15 | Jan 15 | Apr 25 | Jun 24 |
📚 Data Sources
Frost dates: NOAA Climate Normals 1991–2020, National Centers for Environmental Information.Hardiness zones: USDA Plant Hardiness Zone Map, Agricultural Research Service.
Growing requirements: Cooperative Extension Services — NC State, Penn State, University of Florida IFAS.
Companion planting: Cornell University Cooperative Extension.
Data compiled from public agricultural sources. Always verify with your local extension office for micro-climate adjustments.