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When to Plant Broccoli Rabe in Swift County, MN

Swift County, Minnesota Zone 4b May

Top priorities for Swift County, Minnesota gardeners in May

Your garden in Swift County, Minnesota is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 2
Avg. first frost October 4
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Plant out broccoli rabe

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

Get ahead of June
  • Starting indoors: broccoli rabe
  • First harvests: broccoli rabe

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

Swift County, Minnesota is in USDA Zone 4b. The average last spring frost is May 2 and the first fall frost is October 4, giving you a growing season of approximately 155 days.

At an elevation of 1,212 feet, Swift County receives approximately 35.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Broccoli Rabe to ensure they mature before fall.

Swift County, MN (Zone 4b) Moderate season
155 days
Last Spring Frost May 2
155 growing days
First Fall Frost October 4
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Swift County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jun 8 – Jul 13
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 21 Transplant: May 2 🍅 Harvest: Jun 13 – Jul 18
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jun 26 – Jul 31

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Swift County

How your county's soil matches Broccoli Rabe's growing requirements.

Soil pH

Your soil pH (6.3–6.7) is within Broccoli Rabe's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Swift County is excellent for Broccoli Rabe — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Broccoli Rabe.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Broccoli Rabe.

How to Plant Broccoli Rabe

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Broccoli Rabe

4
successive plantings in your 155-day season

Sow every 4.6 weeks. Last sowing by Aug 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 115 gal / 100 sq ft

Monthly Watering Guide for Broccoli Rabe

Broccoli Rabe needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Broccoli Rabe Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 3.5" 4.6" 0" ✅ Rainfall sufficient
Jun 3.5" 4.5" 0" ✅ Rainfall sufficient
Jul 3.5" 3.8" 0" ✅ Rainfall sufficient
Aug 3.5" 3.6" 0" ✅ Rainfall sufficient
Sep 3.5" 2.8" 0.7" 💧 Light watering
Oct 3.5" 2.3" 1.2" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Swift County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Broccoli Rabe Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Broccoli Rabe needs ~612 GDD — county provides 1,898 GDD Excellent fit

Broccoli Rabe Planting Timeline — Swift County, MN

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest June 13 Jun 13 – Jul 18
Fall Sowing July 12 Jul 12 – Jul 26

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

155 days in Swift County

Growing Tips for Broccoli Rabe in Swift County

Direct sow Broccoli Rabe outdoors after May 02 in Swift County when soil has warmed and frost danger has passed.

Your generous 155.0-day season in Swift County allows multiple plantings of Broccoli Rabe. Sow every 20.0 days for continuous harvest.

Common pests for Broccoli Rabe in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Broccoli Rabe in Swift County, MN?

Swift County is in Zone 4b with an average last frost of May 2. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Swift County, MN?

Swift County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 2 and first fall frost is October 4.

🌱

Your Swift County Garden Planner — Free

A 24-page printable planner built for Swift County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Swift County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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