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When to Plant Collard Greens in Richland County, IL

Richland County, Illinois Zone 6b May

Top priorities for Richland County, Illinois gardeners in May

We've pulled the most time-sensitive tasks for Richland County, Illinois this May and put them front and centre. Tackle them in order.

Avg. last frost April 13
Avg. first frost October 27
Soil temp (4") 61°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Indoor seed-starting week for collard greens

    These need a head start before your last frost (April 13). Sow into cells now so you're ready to transplant in a few weeks.

A few tasks this May that'll pay off in June
  • First harvests: collard greens

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Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

Richland County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 27, giving you a growing season of approximately 197 days.

At an elevation of 1,135 feet, Richland County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Collard Greens during the growing season.

Richland County, IL (Zone 6b) Moderate season
197 days
Last Spring Frost April 13
197 growing days
First Fall Frost October 27
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Richland County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (74 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jun 2 – Aug 4
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Aug 10
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Aug 24

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 Richland County

How your county's soil matches Collard Greens's growing requirements.

Soil pH

Your soil pH (6.2–7.0) is within Collard Greens's preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Richland County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.0%) — Collard Greens will thrive.

How to Plant Collard Greens

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 Collard Greens

4
successive plantings in your 197-day season

Sow every 6.3 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

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 Collard Greens

Collard Greens 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 Collard Greens Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.5" 4.3" 0" ✅ Rainfall sufficient
May 3.5" 4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.5" 0" ✅ Rainfall sufficient
Jul 3.5" 4.4" 0" ✅ Rainfall sufficient
Aug 3.5" 4.4" 0" ✅ Rainfall sufficient
Sep 3.5" 3.8" 0" ✅ Rainfall sufficient
Oct 3.5" 3" 0.5" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Collard Greens 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.

Collard Greens needs ~1,186 GDD — county provides 3,595 GDD Excellent fit

Collard Greens Planting Timeline — Richland County, IL

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 8 Jun 8 – Aug 10
Fall Sowing August 18 Aug 18 – Sep 1

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
June Harvest
July Harvest
August Fall Sowing Harvest
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

197 days in Richland County

Growing Tips for Collard Greens in Richland County

Direct sow Collard Greens outdoors after April 13 in Richland County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Richland County, IL?

Richland County is in Zone 6b with an average last frost of April 13. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland County, IL?

Richland County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 27.

🌱

Your Richland County Garden Planner — Free

A 24-page printable planner built for Richland County (Zone 6b). 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 Richland 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.