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

✅ Carrot ✅ Beet ✅ Lettuce ✅ Tomato✅ Pepper✅ Cabbage✅ Strawberries

❌ Bean❌ Pea

Green Onion in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Frequently Asked Questions

When should I plant Green Onion in Zone 3b?

Start Green Onion seeds indoors around Apr 3. Transplant outdoors after May 1. Expect first harvest around Jun 10.

What is the last frost date for Zone 3b?

The average last spring frost date for Zone 3b is May 15. The first fall frost averages Sep 22, giving a 130-day growing season.

Can I grow Green Onion in Zone 3b?

Yes. Green Onion needs 65 days to harvest. Zone 3b has a 130-day growing season, which is sufficient. You can plant up to 3 successions.

What is the best month to plant Green Onion in Zone 3b?

The best time to start Green Onion in Zone 3b is Apr. Begin seeds indoors around Apr 3, then transplant outdoors after the last frost date of May 15.

What companion plants grow well with Green Onion?

Good companion plants for Green Onion include Carrot, Beet, Lettuce, Tomato, Pepper, Cabbage. Avoid planting Green Onion near Bean, Pea.

How long does Green Onion take to harvest?

Green Onion takes approximately 65 days from planting to harvest. In Zone 3b, expect your first harvest around Jun 10.

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