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When to plant Collard Greens in Danforth, IL

In Danforth, plant Collard Greens in spring between April 4 and April 25, once soil temps hold above 50°F. Danforth's last frost averages April 18, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between August 4 and August 18 — roughly 55–75 days before the first frost on October 13.

When to Plant Collard Greens in Danforth, IL

Iroquois County, Illinois Zone 5b August

Top priorities for Iroquois County, Illinois gardeners in August

August is a pivotal month for Iroquois County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 18
Avg. first frost October 13
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs

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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.

Danforth, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 13, giving you a growing season of approximately 178 days.

At an elevation of 1,345 feet, Iroquois County receives approximately 30 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Collard Greens during the growing season.

Danforth, IL (Zone 5b) Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Danforth Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Collard Greens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Aug 10
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 15
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Jul 1 – Sep 2

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 Danforth

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Collard Greens.

Organic Matter

Organic matter is excellent (4.5%) — 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

3
successive plantings in your 178-day season

Sow every 6.3 weeks. Last sowing by Jul 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Collard Greens Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 631 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3.5" 2.8" 0.7" 💧 Light watering
May 3.5" 3.8" 0" ✅ Rainfall sufficient
Jun 3.5" 3.6" 0" ✅ Rainfall sufficient
Jul 3.5" 3" 0.5" 💧 Light watering
Aug 3.5" 2.9" 0.6" 💧 Light watering
Sep 3.5" 3.2" 0.3" 💧 Light watering
Oct 3.5" 2.5" 1" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Iroquois 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 ~894 GDD — county provides 2,447 GDD Excellent fit

Collard Greens Planting Timeline — Danforth, IL

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest June 13 Jun 13 – Aug 15
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · 1-2 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

178 days in Iroquois County

Growing Tips for Collard Greens in Danforth

Direct sow Collard Greens outdoors after April 18 in Iroquois 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 →

When should I plant Collard Greens in Danforth, IL?

In Danforth, IL, plant Collard Greens after the last frost (around April 18) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Danforth, IL for Collard Greens?

Danforth sits in USDA Zone 5b. Collard Greens grows reliably in zones 2a through 11b, so it's a good fit here.

Can Collard Greens grow in Danforth's climate?

Yes — Collard Greens grows well in Danforth's temperate climate. Danforth averages a 178-day frost-free season, with last frost around April 18 and first frost around October 13.

🌱

Your Iroquois County Garden Planner — Free

A 22-page printable planner built for Iroquois County (Zone 5b). 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 Iroquois County, IL. Local conditions may vary. Last updated: August 2026.