Broccoli illustration 🥦

🥦 Growing Broccoli in Zone 3a

Zone 3a has harsh winters and a short growing season. Start Broccoli early indoors to maximize your harvest window. Last frost: May 22. First frost: Sep 12.

Planting Calendar

Indoor
Outdoor
Harvest
Apr 10Sep 12

Season: May 22 – Sep 12 (113 days)

Zone3a
Last FrostMay 22
First FrostSep 12
Season Length113 days
Days to Harvest70
SunFull Sun
Frost ToleranceHeavy
Spacing1/sqft (12" apart)

When to Plant Broccoli in Zone 3a

Start Seeds Indoors: Apr 10

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

Transplant Outdoors: Jun 5

Transplant Broccoli seedlings outdoors after Jun 5. Wait until soil temperature reaches 50°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Aug 4

First harvest approximately Aug 4 (~60 days from transplant). Continue harvesting until first frost (Sep 12).

Fall Planting: Jun 20

For a fall harvest, plant Broccoli around Jun 20 (12 weeks before first frost).

Companion Planting

❌ Strawberries❌ Tomatoes❌ Beans

Frequently Asked Questions

When should I plant Broccoli in Zone 3a?

Start Broccoli seeds indoors around Apr 10. Transplant outdoors after Jun 5. Expect first harvest around Aug 4.

What is the last frost date for Zone 3a?

The average last spring frost date for Zone 3a is May 22. The first fall frost averages Sep 12, giving a 113-day growing season.

Can I grow Broccoli in Zone 3a?

Yes. Broccoli needs 70 days to harvest. Zone 3a has a 113-day growing season, which is sufficient.

What is the best month to plant Broccoli in Zone 3a?

The best time to start Broccoli in Zone 3a is Apr. Begin seeds indoors around Apr 10, then transplant outdoors after the last frost date of May 22.

What companion plants grow well with Broccoli?

Good companion plants for Broccoli include Sage, Rosemary, Mint, Chamomile, Dill. Avoid planting Broccoli near Strawberries, Tomatoes, Beans.

How long does Broccoli take to harvest?

Broccoli takes approximately 70 days from planting to harvest. In Zone 3a, expect your first harvest around Aug 4.

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