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When to Plant Kabocha in USDA Zone 9b

Zone 9b Zone 9b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 9b.

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

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of June
  • First harvests: kabocha
Want it on paper? Download your Zone 9b planting guide →

Kabocha is a Japanese winter squash with an exceptionally sweet, dense, chestnut-like flesh and dark green skin. It is a favorite in Asian cuisine for its rich, dry texture.

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.

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

Kabocha 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 Kabocha planting schedule for that location.

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

Kabocha Planting Calendar — Zone 9b

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors February 1 Feb 1 – Feb 15
Direct Sow January 25 Jan 25 – Feb 15
Harvest May 3 May 3 – May 31

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

85–100 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 Spacing30 inches apart
Row Spacing42 inches between rows

Growing Tips for Kabocha in Zone

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

Direct sow after frost or start indoors. Harvest when the skin is hard and dull. The stem should be dry and corky. Stores well for 3-4 months in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
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Saving Kabocha 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 Kabocha in Zone 9b?

In Zone 9b, plan your Kabocha planting around the average last frost date of January 25. Start seeds indoors around December 28. Direct sow outdoors around January 25. Transplant seedlings around February 1.

Can Kabocha grow in Zone 9b?

Yes, Kabocha can grow well in Zone 9b, hardy in USDA zones 3a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Kabocha (85-100 days to maturity).

When can I harvest Kabocha in Zone 9b?

In Zone 9b, expect to harvest Kabocha from May 3 – May 31. Kabocha takes 85-100 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 Kabocha?

Good companion plants for Kabocha include Corn, Green Beans, Radish. 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.