Blog

When to Plant Napa Cabbage in USDA Zone 9b

Zone 9b Zone 9b May

What to do in May

Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 14
Avg. first frost December 4
  1. Collect napa cabbage at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Download your personalised Zone 9b planting plan →

Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.

In Zone 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.

Share this guide:
Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Napa Cabbage Planting Timeline — Zone 9b

Where Is USDA Zone 9b?

The map below highlights the states that contain Zone 9b. Click any state to see the Napa Cabbage planting schedule for that location.

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

Napa Cabbage Planting Calendar — Zone 9b

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors January 25 Jan 25 – Feb 8
Direct Sow January 4 Jan 4 – Jan 25
Harvest March 22 Mar 22 – Apr 26
Fall Sowing October 25 Oct 25 – Nov 8

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

Month-by-Month Timeline

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

Free Zone 9b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b with start dates, transplant windows, and harvest times.

Instant PDF download. No spam, unsubscribe any time.

Share this guide:

Growing Conditions

Sun

Partial Shade (3-6 hours)

💧 Water

High — keep soil consistently moist

Days to Maturity

55–75 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

329 days (Zone average)

Planting Specifications

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

Succession Planting Napa Cabbage in Zone

7
successive plantings in Zone 's ~329-day season

Sow every 6.3 weeks for continuous harvest throughout the season.

Growing Tips for Napa Cabbage in Zone

Zone has a short growing season (~329 days). Start Napa Cabbage indoors early and use season-extension techniques like row covers and cold frames.

Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
Best Seller
The Gardener's Encyclopedia to Companion Planting

The Gardener's Encyclopedia to Companion Planting

$27 $293 value

The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.

  • Proven pairings for 200+ vegetables, herbs, flowers, and fruits
  • Full seed-starting + planting schedule with timing and spacing
  • Bonus: square-foot gardening guide + printable seasonal planners
See what's inside →

Saving Napa Cabbage 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 Napa Cabbage in Zone 9b?

In Zone 9b, plan your Napa Cabbage planting around the average last frost date of January 25. Start seeds indoors around December 28. Direct sow outdoors around January 4. Transplant seedlings around January 25.

Can Napa Cabbage grow in Zone 9b?

Yes, Napa Cabbage can grow well in Zone 9b, hardy in USDA zones 2a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Napa Cabbage (55-75 days to maturity).

When can I harvest Napa Cabbage in Zone 9b?

In Zone 9b, expect to harvest Napa Cabbage from March 22 – April 26. Napa Cabbage takes 55-75 days from planting to harvest.

What is the last frost date for Zone 9b?

The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Napa Cabbage?

Good companion plants for Napa Cabbage include Celery, Onion, Beets. 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: May 2026.

Sources & credits

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