Green Onion illustration

Growing Green Onion in Zone 3b

Zone 3b has harsh winters and a short growing season. Start Green Onion early indoors to maximize your harvest window. Last frost: May 15. First frost: Sep 22.

Planting Calendar

Indoor
Outdoor
Harvest
Apr 3Sep 22

Season: May 15 – Sep 22 (130 days) · Succession: plant every 3 weeks (up to 3x)

Zone3b
Last FrostMay 15
First FrostSep 22
Season Length130 days
Days to Harvest65
Sunfull-to-part
Frost ToleranceHeavy
Spacing16/sqft (3" apart)

When to Plant Green Onion in Zone 3b

Start Seeds Indoors: Apr 3

Start Green Onion seeds indoors around Apr 3 (6 weeks before last frost). Optimal germination temperature: 65°F. Germinates in 7–14 days.

Transplant Outdoors: May 1

Transplant Green Onion seedlings outdoors after May 1. Wait until soil temperature reaches 40°F. Space plants at 16/sqft (3" apart). Harden off plants for a week before moving outside.

Harvest: Jun 10

First harvest approximately Jun 10 (~40 days from transplant). Continue harvesting until first frost (Sep 22). Green Onion can overwinter in mild climates for continued harvest.

Fall Planting: Jul 28

For a fall harvest, plant Green Onion around Jul 28 (8 weeks before first frost).

Companion Planting

❌ Bean❌ Pea

Plan Your Green Onion Garden

Track Green Onion from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Green Onion Growing Guide