Growing Brussels Sprouts in Zone 9a

Zone 9a has warm winters and an extended growing season — excellent for heat-loving crops like Brussels Sprouts. Last frost: Mar 20. First frost: Nov 12.

Planting Calendar

Indoor

Outdoor

Harvest

Feb 6Nov 12

Season: Mar 20 – Nov 12 (237 days)

Zone9a

Last FrostMar 20

First FrostNov 12

Season Length237 days

Days to Harvest100

SunFull Sun

Frost ToleranceModerate

Spacing24/sqft

When to Plant Brussels Sprouts in Zone 9a

Start Seeds Indoors: Feb 6

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

Transplant Outdoors: Mar 6

Transplant Brussels Sprouts seedlings outdoors after Mar 6. Wait until soil temperature reaches 50°F. Space plants at 24/sqft. Harden off plants for a week before moving outside.

Harvest: Jun 4

First harvest approximately Jun 4 (~90 days from transplant). Continue harvesting until first frost (Nov 12).

Fall Planting: Jul 23

For a fall harvest, plant Brussels Sprouts around Jul 23 (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 9a?

Start Brussels Sprouts seeds indoors around Feb 6. Transplant outdoors after Mar 6. Expect first harvest around Jun 4.

What is the last frost date for Zone 9a?

The average last spring frost date for Zone 9a is Mar 20. The first fall frost averages Nov 12, giving a 237-day growing season.

Can I grow Brussels Sprouts in Zone 9a?

Yes. Brussels Sprouts needs 100 days to harvest. Zone 9a has a 237-day growing season, which is sufficient.

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

The best time to start Brussels Sprouts in Zone 9a is Feb. Begin seeds indoors around Feb 6, then transplant outdoors after the last frost date of Mar 20.

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 9a, expect your first harvest around Jun 4.

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