Growing Brussels Sprouts in Zone 9b

Zone 9b has warm winters and an extended growing season — excellent for heat-loving crops like Brussels Sprouts. Last frost: Mar 10. First frost: Nov 15.

Planting Calendar

Indoor

Outdoor

Harvest

Jan 27Nov 15

Season: Mar 10 – Nov 15 (250 days)

Zone9b

Last FrostMar 10

First FrostNov 15

Season Length250 days

Days to Harvest100

SunFull Sun

Frost ToleranceModerate

Spacing24/sqft

When to Plant Brussels Sprouts in Zone 9b

Start Seeds Indoors: Jan 27

Start Brussels Sprouts seeds indoors around Jan 27 (6 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 5–10 days.

Transplant Outdoors: Feb 24

Transplant Brussels Sprouts seedlings outdoors after Feb 24. Wait until soil temperature reaches 50°F. Space plants at 24/sqft. Harden off plants for a week before moving outside.

Harvest: May 25

First harvest approximately May 25 (~90 days from transplant). Continue harvesting until first frost (Nov 15).

Fall Planting: Jul 26

For a fall harvest, plant Brussels Sprouts around Jul 26 (16 weeks before first frost).

Companion Planting

✅ Thyme✅ Nasturtiums✅ Onions✅ Garlic

❌ Beans❌ Strawberries

Brussels Sprouts in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Frequently Asked Questions

When should I plant Brussels Sprouts in Zone 9b?

Start Brussels Sprouts seeds indoors around Jan 27. Transplant outdoors after Feb 24. Expect first harvest around May 25.

What is the last frost date for Zone 9b?

The average last spring frost date for Zone 9b is Mar 10. The first fall frost averages Nov 15, giving a 250-day growing season.

Can I grow Brussels Sprouts in Zone 9b?

Yes. Brussels Sprouts needs 100 days to harvest. Zone 9b has a 250-day growing season, which is sufficient.

What is the best month to plant Brussels Sprouts in Zone 9b?

The best time to start Brussels Sprouts in Zone 9b is Jan. Begin seeds indoors around Jan 27, then transplant outdoors after the last frost date of Mar 10.

What companion plants grow well with Brussels Sprouts?

Good companion plants for Brussels Sprouts include Thyme, Nasturtiums, Onions, Garlic. Avoid planting Brussels Sprouts near Beans, Strawberries.

How long does Brussels Sprouts take to harvest?

Brussels Sprouts takes approximately 100 days from planting to harvest. In Zone 9b, expect your first harvest around May 25.

Plan Your Brussels Sprouts Garden

Track Brussels Sprouts from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Brussels Sprouts Growing Guide