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When to Plant Broccoli Rabe in USDA Zone 4b

Zone 4b Zone 4b May

What to do in May

May is a pivotal month for Zone 4b gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 11
Avg. first frost October 2
  1. Harden off and plant broccoli rabe

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Seed broccoli rabe outdoors

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Before June arrives, get these ready
  • Starting indoors: broccoli rabe
  • First harvests: broccoli rabe
Send me my free Zone 4b Planting Guide →

Broccoli rabe (rapini) is a brassica grown for its slightly bitter, nutty-flavored florets, leaves, and stems. It is a staple in Italian cooking.

In Zone 4b, the average last spring frost is around May 1 and the first fall frost is around October 3, giving you a growing season of approximately 155 days.

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Zone 4b Moderate season
155 days
Last Spring Frost May 1
155 growing days
First Fall Frost October 3

Broccoli Rabe Planting Timeline — Zone 4b

Where Is USDA Zone 4b?

The map below highlights the states that contain Zone 4b. Click any state to see the Broccoli Rabe planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Broccoli Rabe Planting Calendar — Zone 4b

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest June 12 Jun 12 – Jul 17
Fall Sowing July 11 Jul 11 – Jul 25

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August
September
October
November
December

Free Zone 4b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

40–60 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

155 days (Zone average)

Planting Specifications

Planting Depth1 inches
Plant Spacing15 inches apart
Row Spacing24 inches between rows

Succession Planting Broccoli Rabe in Zone

4
successive plantings in Zone 's ~155-day season

Sow every 4.6 weeks for continuous harvest throughout the season.

Growing Tips for Broccoli Rabe in Zone

Zone has a short growing season (~155 days). Start Broccoli Rabe indoors early and use season-extension techniques like row covers and cold frames.

Direct sow in spring or fall. Harvest when small yellow flower buds first appear but before they open. Cut the main shoot first to encourage side shoots.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
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Saving Broccoli Rabe Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Broccoli Rabe in Zone 4b?

In Zone 4b, plan your Broccoli Rabe planting around the average last frost date of May 1. Start seeds indoors around March 20. Direct sow outdoors around April 24. Transplant seedlings around May 1.

Can Broccoli Rabe grow in Zone 4b?

Yes, Broccoli Rabe can grow well in Zone 4b, hardy in USDA zones 2a through 10b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Broccoli Rabe (40-60 days to maturity).

When can I harvest Broccoli Rabe in Zone 4b?

In Zone 4b, expect to harvest Broccoli Rabe from June 12 – July 17. Broccoli Rabe takes 40-60 days from planting to harvest.

What is the last frost date for Zone 4b?

The average last spring frost in Zone 4b is around May 1, and the first fall frost is around October 3. This gives a growing season of approximately 155 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Broccoli Rabe?

Good companion plants for Broccoli Rabe include Onion, Garlic, Celery. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.