Growing Brussels Sprouts in Zone 3b

Zone 3b has harsh winters and a short growing season. Start Brussels Sprouts early indoors to maximize your harvest window. Last frost: May 15. First frost: Sep 22.

Planting Calendar

Indoor

Outdoor

Harvest

Apr 3Sep 22

Season: May 15 – Sep 22 (130 days)

Zone3b

Last FrostMay 15

First FrostSep 22

Season Length130 days

Days to Harvest100

SunFull Sun

Frost ToleranceModerate

Spacing24/sqft

When to Plant Brussels Sprouts in Zone 3b

Start Seeds Indoors: Apr 3

Start Brussels Sprouts seeds indoors around Apr 3 (6 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 5–10 days.

Transplant Outdoors: May 1

Transplant Brussels Sprouts seedlings outdoors after May 1. Wait until soil temperature reaches 50°F. Space plants at 24/sqft. Harden off plants for a week before moving outside.

Harvest: Jul 30

First harvest approximately Jul 30 (~90 days from transplant). Continue harvesting until first frost (Sep 22).

Fall Planting: Jun 2

For a fall harvest, plant Brussels Sprouts around Jun 2 (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 3b?

Start Brussels Sprouts seeds indoors around Apr 3. Transplant outdoors after May 1. Expect first harvest around Jul 30.

What is the last frost date for Zone 3b?

The average last spring frost date for Zone 3b is May 15. The first fall frost averages Sep 22, giving a 130-day growing season.

Can I grow Brussels Sprouts in Zone 3b?

Yes. Brussels Sprouts needs 100 days to harvest. Zone 3b has a 130-day growing season, which is sufficient.

What is the best month to plant Brussels Sprouts in Zone 3b?

The best time to start Brussels Sprouts in Zone 3b is Apr. Begin seeds indoors around Apr 3, then transplant outdoors after the last frost date of May 15.

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 3b, expect your first harvest around Jul 30.

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