Onion Planting Guide

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

Planting Schedule by Zone

Select your USDA zone below for a detailed guide with tips specific to your region.

Zone 3 Zone 3a Zone 3b Zone 4 Zone 4a Zone 4b Zone 5 Zone 5a Zone 5b Zone 6 Zone 6a Zone 6b Zone 7 Zone 7a Zone 7b Zone 8 Zone 8a Zone 8b Zone 9 Zone 9a Zone 9b Zone 10 Zone 10a Zone 10b Zone 11 Zone 11a Zone 11b

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

What you'll need — Your Zone

🛒 Onion — Seeds & Supplies

🌱 Onion Seeds

Search for these at your local garden center or nursery.

Companion Planting

Companion planting improves growth, deters pests, and makes better use of garden space.

✓ Good Companions

Carrot Beet Lettuce

✗ Avoid Nearby

Beans Peas

📚 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.