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When to Plant Leeks in USDA Zone 5b

Zone 5b Zone 5b April

Zone 5b gardeners: here's your April plan

Welcome to April in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 27
Avg. first frost October 16
  1. Transplant leeks outside

    Frost risk is low now in Zone 5b. If you've been covering beds overnight, you can stop.

  2. Plant leeks from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Get your free Zone 5b 2026 Planting Guide →
Leeks

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 5b, the average last spring frost is around April 18 and the first fall frost is around October 13, giving you a growing season of approximately 178 days.

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Zone 5b Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Leeks Planting Timeline — Zone 5b

Where Is USDA Zone 5b?

The map below highlights the states that contain Zone 5b. 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 5b

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest July 18 Jul 18 – Oct 3
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

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

Free Zone 5b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 5b with start dates, transplant windows, and harvest times.

Instant PDF download. No spam, unsubscribe any time.

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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

°F to °F average annual minimum

Growing Season

178 days (Zone average)

Planting Specifications

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

Growing Tips for Leeks in Zone

Zone has a short growing season (~178 days). Start Leeks indoors early and use season-extension techniques like row covers and cold frames.

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
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Saving Leeks Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

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

🏷️
Garden Plant Markers $6-12

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

Related Plants

Frequently Asked Questions

When should I plant Leeks in Zone 5b?

In Zone 5b, plan your Leeks planting around the average last frost date of April 18. Start seeds indoors around March 14. Direct sow outdoors around April 4. Transplant seedlings around April 18.

Can Leeks grow in Zone 5b?

Yes, Leeks can grow well in Zone 5b, hardy in USDA zones 3a through 10b. Zone 5b has a growing season of approximately 178 days, which is sufficient for Leeks (90-150 days to maturity).

When can I harvest Leeks in Zone 5b?

In Zone 5b, expect to harvest Leeks from July 18 – October 3. Leeks takes 90-150 days from planting to harvest.

What is the last frost date for Zone 5b?

The average last spring frost in Zone 5b is around April 18, and the first fall frost is around October 13. This gives a growing season of approximately 178 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.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

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.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.