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

Plan Your Leek Garden

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

Start Free Leek Growing Guide