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When to Plant Leeks in USDA Zone 6b

Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

In Zone 6b, the average last spring frost is around April 3 and the first fall frost is around October 25, giving you a growing season of approximately 205 days.

Zone 6b Long season
205 days
Last Spring Frost April 3
205 growing days
First Fall Frost October 25

Leeks Planting Timeline — Zone 6b

Where Is USDA Zone 6b?

The map below highlights the states that contain Zone 6b. Click any state to see the Leeks planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Leeks Planting Calendar — Zone 6b

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Harvest July 3 Jul 3 – Sep 18
Fall Sowing August 16 Aug 16 – Aug 30

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June
July Harvest
August Fall Sowing Harvest
September Harvest
October
November
December

Free Zone 6b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 6b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

90–150 days

Soil pH

6 – 7

Zone Temperature Range

-5°F to 0°F average annual minimum

Growing Season

205 days (Zone 6b average)

Planting Specifications

Planting Depth1 inches
Plant Spacing15 inches apart
Row Spacing24 inches between rows

Growing Tips for Leeks in Zone 6b

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Level Up Your Garden

Saving Leeks Seeds

Recommended for Your Garden

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Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

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Frequently Asked Questions

When should I plant Leeks in Zone 6b?

In Zone 6b, plan your Leeks planting around the average last frost date of April 3. Start seeds indoors around February 27. Direct sow outdoors around March 20. Transplant seedlings around April 3.

Can Leeks grow in Zone 6b?

Yes, Leeks can grow well in Zone 6b, hardy in USDA zones 3a through 10b. Zone 6b has a growing season of approximately 205 days, which is sufficient for Leeks (90-150 days to maturity).

When can I harvest Leeks in Zone 6b?

In Zone 6b, expect to harvest Leeks from July 3 – September 18. Leeks takes 90-150 days from planting to harvest.

What is the last frost date for Zone 6b?

The average last spring frost in Zone 6b is around April 3, and the first fall frost is around October 25. This gives a growing season of approximately 205 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Leeks?

Good companion plants for Leeks include Carrots, Celery, Lettuce. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 6b, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.