Growing Leek in Zone 3b

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

Planting Calendar

Indoor

Outdoor

Harvest

Mar 6Sep 22

Season: May 15 – Sep 22 (130 days)

Zone3b

Last FrostMay 15

First FrostSep 22

Season Length130 days

Days to Harvest120

SunFull Sun

Frost ToleranceModerate

Spacing4/sqft (6" apart)

When to Plant Leek in Zone 3b

Start Seeds Indoors: Mar 6

Start Leek seeds indoors around Mar 6 (10 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 7–14 days.

Transplant Outdoors: May 1

Transplant Leek seedlings outdoors after May 1. Wait until soil temperature reaches 45°F. Space plants at 4/sqft (6" apart). Harden off plants for a week before moving outside.

Harvest: Jul 30

First harvest approximately Jul 30 (~90 days from transplant). Continue harvesting until first frost (Sep 22). Leek can overwinter in mild climates for continued harvest.

Companion Planting

✅ Carrots✅ Onions✅ Celery

❌ Beans❌ Peas

Leek 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 Leek in Zone 3b?

Start Leek seeds indoors around Mar 6. Transplant outdoors after May 1. Expect first harvest around Jul 30.

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 Leek in Zone 3b?

Yes. Leek needs 120 days to harvest. Zone 3b has a 130-day growing season, which is sufficient.

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

The best time to start Leek in Zone 3b is Mar. Begin seeds indoors around Mar 6, then transplant outdoors after the last frost date of May 15.

What companion plants grow well with Leek?

Good companion plants for Leek include Carrots, Onions, Celery. Avoid planting Leek near Beans, Peas.

How long does Leek take to harvest?

Leek takes approximately 120 days from planting to harvest. In Zone 3b, expect your first harvest around Jul 30.

Plan Your Leek Garden

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

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