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When to Plant Broccoli in USDA Zone 9b

Zone 9b Zone 9b May

Your May planting checklist for Zone 9b

May is a pivotal month for Zone 9b gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 14
Avg. first frost December 4
  1. It's harvest week for broccoli

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Get the full Zone 9b Garden Planner — free →
Broccoli

Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.

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

Broccoli 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 Broccoli planting schedule for that location.

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

Broccoli 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 29 Mar 29 – May 10
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 Harvest
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.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Moderate — regular watering

Days to Maturity

60–90 days

Soil pH

6 – 7

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 Broccoli in Zone

6
successive plantings in Zone 's ~329-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Broccoli in Zone

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

Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries
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Saving Broccoli Seeds

🌾 Save Your Own Broccoli Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow plants to flower 2nd year; collect dry pods.
Storage Store airtight; viable 5 years at 35°F, under 50% humidity.

Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.

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 Broccoli in Zone 9b?

In Zone 9b, plan your Broccoli 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 Broccoli grow in Zone 9b?

Yes, Broccoli 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 Broccoli (60-90 days to maturity).

When can I harvest Broccoli in Zone 9b?

In Zone 9b, expect to harvest Broccoli from March 29 – May 10. Broccoli takes 60-90 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 Broccoli?

Good companion plants for Broccoli include Celery, Onion, Potatoes, Dill. 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.