Green Onion illustration

Growing Green Onion in Zone 4b

Zone 4b has cold winters and a moderate growing season. Timing is key for Green Onion in this zone. Last frost: May 1. First frost: Oct 5.

Planting Calendar

Indoor
Outdoor
Harvest
Mar 20Oct 5

Season: May 1 – Oct 5 (157 days) · Succession: plant every 3 weeks (up to 4x)

Zone4b
Last FrostMay 1
First FrostOct 5
Season Length157 days
Days to Harvest65
Sunfull-to-part
Frost ToleranceHeavy
Spacing16/sqft (3" apart)

When to Plant Green Onion in Zone 4b

Start Seeds Indoors: Mar 20

Start Green Onion seeds indoors around Mar 20 (6 weeks before last frost). Optimal germination temperature: 65°F. Germinates in 7–14 days.

Transplant Outdoors: Apr 17

Transplant Green Onion seedlings outdoors after Apr 17. Wait until soil temperature reaches 40°F. Space plants at 16/sqft (3" apart). Harden off plants for a week before moving outside.

Harvest: May 27

First harvest approximately May 27 (~40 days from transplant). Continue harvesting until first frost (Oct 5). Green Onion can overwinter in mild climates for continued harvest.

Fall Planting: Aug 10

For a fall harvest, plant Green Onion around Aug 10 (8 weeks before first frost).

Companion Planting

❌ Bean❌ Pea

Frequently Asked Questions

When should I plant Green Onion in Zone 4b?

Start Green Onion seeds indoors around Mar 20. Transplant outdoors after Apr 17. Expect first harvest around May 27.

What is the last frost date for Zone 4b?

The average last spring frost date for Zone 4b is May 1. The first fall frost averages Oct 5, giving a 157-day growing season.

Can I grow Green Onion in Zone 4b?

Yes. Green Onion needs 65 days to harvest. Zone 4b has a 157-day growing season, which is sufficient. You can plant up to 4 successions.

What is the best month to plant Green Onion in Zone 4b?

The best time to start Green Onion in Zone 4b is Mar. Begin seeds indoors around Mar 20, then transplant outdoors after the last frost date of May 1.

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 4b, expect your first harvest around May 27.

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