Leek illustration

Growing Leek in Zone 4b

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

Planting Calendar

Indoor
Outdoor
Harvest
Feb 20Oct 5

Season: May 1 – Oct 5 (157 days)

Zone4b
Last FrostMay 1
First FrostOct 5
Season Length157 days
Days to Harvest120
SunFull Sun
Frost ToleranceModerate
Spacing4/sqft (6" apart)

When to Plant Leek in Zone 4b

Start Seeds Indoors: Feb 20

Start Leek seeds indoors around Feb 20 (10 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 7–14 days.

Transplant Outdoors: Apr 17

Transplant Leek seedlings outdoors after Apr 17. 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 16

First harvest approximately Jul 16 (~90 days from transplant). Continue harvesting until first frost (Oct 5). Leek can overwinter in mild climates for continued harvest.

Companion Planting

✅ Carrots✅ Onions✅ Celery
❌ Beans❌ Peas

Frequently Asked Questions

When should I plant Leek in Zone 4b?

Start Leek seeds indoors around Feb 20. Transplant outdoors after Apr 17. Expect first harvest around Jul 16.

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 Leek in Zone 4b?

Yes. Leek needs 120 days to harvest. Zone 4b has a 157-day growing season, which is sufficient.

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

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

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 4b, expect your first harvest around Jul 16.

Plan Your Leek Garden

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

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