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When to plant Collard Greens in Olean, MO

For Collard Greens in Olean, the safe spring window opens around March 23 and closes around April 13. Last expected frost is April 6, first fall frost October 27, giving a 204-day growing season. A second sowing from August 18 to September 1 extends the harvest into fall.

When to Plant Collard Greens in Olean, MO

Miller County, Missouri Zone 6b August

August in the garden — Miller County, Missouri

Welcome to August in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 6
Avg. first frost October 27
Soil temp (4") 82°F
Watering Moderate
Pest pressure High
Daylight 13.5 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.

Olean, Missouri is in USDA Zone 6b. The average last spring frost is April 6 and the first fall frost is October 27, giving you a growing season of approximately 204 days.

At an elevation of 1,086 feet, Miller County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Collard Greens during the growing season.

Olean, MO (Zone 6b) Long season
204 days
Last Spring Frost April 6
204 growing days
First Fall Frost October 27

Olean Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Collard Greens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: May 26 – Jul 28
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: Jun 1 – Aug 3
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 16 – Aug 18

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 Olean

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

Soil pH

Your soil pH (5.7–6.7) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Miller 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 moderate (2.4%). Annual compost additions will help Collard Greens.

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 204-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.

Collard Greens Water Budget

Plant needs
0.8″/week
Rainfall provides
0.6″/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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3.5" 3.4" 0.1" 💧 Light watering
May 3.5" 4.2" 0" ✅ Rainfall sufficient
Jun 3.5" 3.6" 0" ✅ Rainfall sufficient
Jul 3.5" 3.1" 0.4" 💧 Light watering
Aug 3.5" 3.1" 0.4" 💧 Light watering
Sep 3.5" 3.1" 0.4" 💧 Light watering
Oct 3.5" 2.4" 1.1" 💧 Light watering
Nov 1.8" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Miller 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 ~1,089 GDD — county provides 3,417 GDD Excellent fit

Collard Greens Planting Timeline — Olean, MO

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors April 6 Apr 6 – Apr 20
Direct Sow March 23 Mar 23 – Apr 13
Harvest June 1 Jun 1 – Aug 3
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

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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

204 days in Miller County

Growing Tips for Collard Greens in Olean

Direct sow Collard Greens outdoors after April 06 in Miller 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 Olean, MO?

In Olean, MO, plant Collard Greens after the last frost (around April 6) and before the first frost (around October 27). Best results when soil holds above 50°F.

What growing zone is Olean, MO for Collard Greens?

Olean sits in USDA Zone 6b. Collard Greens grows reliably in zones 2a through 11b, so it's a good fit here.

Can Collard Greens grow in Olean's climate?

Yes — Collard Greens grows well in Olean's temperate climate. Olean averages a 204-day frost-free season, with last frost around April 6 and first frost around October 27.

🌱

Your Miller County Garden Planner — Free

A 22-page printable planner built for Miller 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 Miller County, MO. Local conditions may vary. Last updated: August 2026.