Growing Green Onion in Zone 4a

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

Planting Calendar

Indoor

Outdoor

Harvest

Mar 24Oct 1

Season: May 5 – Oct 1 (149 days) · Succession: plant every 3 weeks (up to 4x)

Zone4a

Last FrostMay 5

First FrostOct 1

Season Length149 days

Days to Harvest65

Sunfull-to-part

Frost ToleranceHeavy

Spacing16/sqft (3" apart)

When to Plant Green Onion in Zone 4a

Start Seeds Indoors: Mar 24

Start Green Onion seeds indoors around Mar 24 (6 weeks before last frost). Optimal germination temperature: 65°F. Germinates in 7–14 days.

Transplant Outdoors: Apr 21

Transplant Green Onion seedlings outdoors after Apr 21. 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 31

First harvest approximately May 31 (~40 days from transplant). Continue harvesting until first frost (Oct 1). Green Onion can overwinter in mild climates for continued harvest.

Fall Planting: Aug 6

For a fall harvest, plant Green Onion around Aug 6 (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 4a?

Start Green Onion seeds indoors around Mar 24. Transplant outdoors after Apr 21. Expect first harvest around May 31.

What is the last frost date for Zone 4a?

The average last spring frost date for Zone 4a is May 5. The first fall frost averages Oct 1, giving a 149-day growing season.

Can I grow Green Onion in Zone 4a?

Yes. Green Onion needs 65 days to harvest. Zone 4a has a 149-day growing season, which is sufficient. You can plant up to 4 successions.

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

The best time to start Green Onion in Zone 4a is Mar. Begin seeds indoors around Mar 24, then transplant outdoors after the last frost date of May 5.

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 4a, expect your first harvest around May 31.

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