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When to Plant Brussels Sprouts in USDA Zone 9a

Zone 9a Zone 9a April

Your April planting checklist for Zone 9a

If you only do a handful of things in the garden this April, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 14
Avg. first frost December 5
A few tasks this April that'll pay off in May
  • First harvests: brussels sprouts
Get the full Zone 9a Garden Planner — free →
Brussels Sprouts

Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.

In Zone 9a, the average last spring frost is around February 10 and the first fall frost is around December 10, giving you a growing season of approximately 303 days.

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Zone 9a Year-round
303 days
Last Spring Frost February 10
303 growing days
First Fall Frost December 10

Brussels Sprouts Planting Timeline — Zone 9a

Where Is USDA Zone 9a?

The map below highlights the states that contain Zone 9a. Click any state to see the Brussels Sprouts planting schedule for that location.

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

Brussels Sprouts Planting Calendar — Zone 9a

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors February 10 Feb 10 – Feb 24
Direct Sow January 20 Jan 20 – Feb 10
Harvest May 12 May 12 – Jul 7
Fall Sowing October 15 Oct 15 – Oct 29

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

Month-by-Month Timeline

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

Free Zone 9a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9a 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

90–130 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

303 days (Zone average)

Planting Specifications

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

Growing Tips for Brussels Sprouts in Zone

Zone has a short growing season (~303 days). Start Brussels Sprouts indoors early and use season-extension techniques like row covers and cold frames.

Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries
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Saving Brussels Sprouts Seeds

Recommended for Your Garden

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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.

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Garden Plant Markers $6-12

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

Related Plants

Frequently Asked Questions

When should I plant Brussels Sprouts in Zone 9a?

In Zone 9a, plan your Brussels Sprouts planting around the average last frost date of February 10. Start seeds indoors around January 13. Direct sow outdoors around January 20. Transplant seedlings around February 10.

Can Brussels Sprouts grow in Zone 9a?

Yes, Brussels Sprouts can grow well in Zone 9a, hardy in USDA zones 2a through 10b. Zone 9a has a growing season of approximately 303 days, which is sufficient for Brussels Sprouts (90-130 days to maturity).

When can I harvest Brussels Sprouts in Zone 9a?

In Zone 9a, expect to harvest Brussels Sprouts from May 12 – July 7. Brussels Sprouts takes 90-130 days from planting to harvest.

What is the last frost date for Zone 9a?

The average last spring frost in Zone 9a is around February 10, and the first fall frost is around December 10. This gives a growing season of approximately 303 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Brussels Sprouts?

Good companion plants for Brussels Sprouts include Carrots, Celery, Dill, Sage. 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: April 2026.

Sources & credits

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