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When to Plant Broccoli Rabe in Champaign County, IL

Champaign County, Illinois Zone 6a May

May in the garden — Champaign County, Illinois

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

Avg. last frost April 14
Avg. first frost October 19
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Start broccoli rabe indoors

    These need a head start before your last frost (April 14). Sow into cells now so you're ready to transplant in a few weeks.

  2. Bring in the broccoli rabe

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of June
  • 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.

Champaign County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 19, giving you a growing season of approximately 188 days.

At an elevation of 1,215 feet, Champaign County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Broccoli Rabe during the growing season.

Champaign County, IL (Zone 6a) Moderate season
188 days
Last Spring Frost April 14
188 growing days
First Fall Frost October 19

Champaign County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: May 20 – Jun 24
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: May 26 – Jun 30
Safe Start (90%) ✓ Fits season (114 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 5 – Jul 10

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 Champaign County

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

Soil pH

Your soil pH (5.9–6.8) overlaps with Broccoli Rabe's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Broccoli Rabe will thrive.

How to Plant Broccoli Rabe

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Broccoli Rabe

5
successive plantings in your 188-day season

Sow every 4.6 weeks. Last sowing by Aug 20 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 2.5" 0" ❄️ Dormant
Apr 3.5" 3.6" 0" ✅ Rainfall sufficient
May 3.5" 4.6" 0" ✅ Rainfall sufficient
Jun 3.5" 4.5" 0" ✅ Rainfall sufficient
Jul 3.5" 4.4" 0" ✅ Rainfall sufficient
Aug 3.5" 3.9" 0" ✅ Rainfall sufficient
Sep 3.5" 4" 0" ✅ Rainfall sufficient
Oct 3.5" 3.1" 0.4" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Champaign 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 ~762 GDD — county provides 2,867 GDD Excellent fit

Broccoli Rabe Planting Timeline — Champaign County, IL

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 14 Apr 14 – Apr 28
Direct Sow March 31 Mar 31 – Apr 21
Harvest May 26 May 26 – Jun 30
Fall Sowing August 10 Aug 10 – Aug 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

188 days in Champaign County

Growing Tips for Broccoli Rabe in Champaign County

Direct sow Broccoli Rabe outdoors after April 14 in Champaign County when soil has warmed and frost danger has passed.

Your generous 188.0-day season in Champaign 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 Champaign County, IL?

Champaign County is in Zone 6a with an average last frost of April 14. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Champaign County, IL?

Champaign County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 19.

🌱

Your Champaign County Garden Planner — Free

A 24-page printable planner built for Champaign County (Zone 6a). 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 Champaign County, IL. 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.