When should I plant Broccoli in Zone 3b?

Start Broccoli seeds indoors around Apr 3. Transplant outdoors after May 29. Expect first harvest around Jul 28.

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 Broccoli in Zone 3b?

Yes. Broccoli needs 70 days to harvest. Zone 3b has a 130-day growing season, which is sufficient.

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🥦 Growing Broccoli in Zone 3b

Zone 3b has harsh winters and a short growing season. Start Broccoli 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 Harvest70

SunFull Sun

Frost ToleranceHeavy

Spacing1/sqft (12" apart)

When to Plant Broccoli in Zone 3b

Start Seeds Indoors: Apr 3

Start Broccoli seeds indoors around Apr 3 (6 weeks before last frost). Optimal germination temperature: 75°F. Germinates in 5–10 days.

Transplant Outdoors: May 29

Transplant Broccoli seedlings outdoors after May 29. Wait until soil temperature reaches 50°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Jul 28

First harvest approximately Jul 28 (~60 days from transplant). Continue harvesting until first frost (Sep 22).

Fall Planting: Jun 30

For a fall harvest, plant Broccoli around Jun 30 (12 weeks before first frost).

Companion Planting

✅ Sage ✅ Rosemary ✅ Mint ✅ Chamomile ✅ Dill

❌ Strawberries❌ Tomatoes❌ Beans

Broccoli 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

Plan Your Broccoli Garden

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

Start Free Broccoli Growing Guide