Korean Small Onion illustration

Growing Korean Small Onion in Zone 4a

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

Planting Calendar

Outdoor
Harvest
Apr 7Oct 1

Season: May 5 – Oct 1 (149 days)

Zone4a
Last FrostMay 5
First FrostOct 1
Season Length149 days
Days to Harvest65
SunFull Sun
Frost ToleranceHeavy
Spacing16/sqft (3" apart)

When to Plant Korean Small Onion in Zone 4a

Harvest: May 17

First harvest approximately May 17 (~40 days from transplant). Continue harvesting until first frost (Oct 1). Korean Small Onion can overwinter in mild climates for continued harvest.

Fall Planting: Aug 20

For a fall harvest, plant Korean Small Onion around Aug 20 (6 weeks before first frost).

Companion Planting

❌ Bean❌ Pea

Frequently Asked Questions

When should I plant Korean Small Onion in Zone 4a?

Direct sow Korean Small Onion outdoors around May 5. Harvest around May 17.

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 Korean Small Onion in Zone 4a?

Yes. Korean Small Onion needs 65 days to harvest. Zone 4a has a 149-day growing season, which is sufficient.

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

The best time to plant Korean Small Onion in Zone 4a is around May 5, when soil temperatures are suitable and frost risk has passed.

What companion plants grow well with Korean Small Onion?

Good companion plants for Korean Small Onion include Carrot, Beet, Lettuce. Avoid planting Korean Small Onion near Bean, Pea.

How long does Korean Small Onion take to harvest?

Korean Small Onion takes approximately 65 days from planting to harvest. In Zone 4a, expect your first harvest around May 17.

Plan Your Korean Small Onion Garden

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

Start Free Korean Small Onion Growing Guide