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When to Plant Leeks in USDA Zone 10b

Zone 10b Zone 10b May

May in Zone 10b — your action list

Welcome to May in Zone 10b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 13
Avg. first frost November 27
  1. It's harvest week for leeks

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Looking ahead to June
  • First harvests: leeks
Send me my free Zone 10b 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 10b, the average last spring frost is around January 1 and the first fall frost is around December 31, giving you a growing season of approximately 364 days.

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Zone 10b Year-round
364 days
Last Spring Frost January 1
364 growing days
First Fall Frost December 31

Leeks Planting Timeline — Zone 10b

Where Is USDA Zone 10b?

The map below highlights the states that contain Zone 10b. 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 10b

Activity When Date Range
Start Indoors December 4 Dec 4 – Dec 18
Transplant Outdoors January 1 Jan 1 – Jan 15
Direct Sow December 11 Dec 11 – Jan 1
Harvest April 2 Apr 2 – Jun 18
Fall Sowing November 5 Nov 5 – Nov 19

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

Month-by-Month Timeline

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

Free Zone 10b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 10b 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

°F to °F average annual minimum

Growing Season

364 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 (~364 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 10b?

In Zone 10b, plan your Leeks planting around the average last frost date of January 1. Start seeds indoors around December 4. Direct sow outdoors around December 11. Transplant seedlings around January 1.

Can Leeks grow in Zone 10b?

Yes, Leeks can grow well in Zone 10b, hardy in USDA zones 3a through 10b. Zone 10b has a growing season of approximately 364 days, which is sufficient for Leeks (90-150 days to maturity).

When can I harvest Leeks in Zone 10b?

In Zone 10b, expect to harvest Leeks from April 2 – June 18. Leeks takes 90-150 days from planting to harvest.

What is the last frost date for Zone 10b?

The average last spring frost in Zone 10b is around January 1, and the first fall frost is around December 31. This gives a growing season of approximately 364 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.

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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: May 2026.

Sources & credits

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