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When to Plant Collard Greens in Pitkin County, CO

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.

Pitkin County, Colorado is in USDA Zone 4a. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 6,411 feet, Pitkin County receives approximately 17.8 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Collard Greens to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Collard Greens successfully. Mulch heavily to conserve soil moisture.

Pitkin County, CO (Zone 4a) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Pitkin County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 24 Transplant: Jun 5 🍅 Harvest: Jul 31 – Oct 2
Recommended (50%) ✗ May not fit
Start indoors: May 5 Transplant: Jun 16 🍅 Harvest: Aug 11 – Oct 13
Safe Start (90%) ✗ May not fit
Start indoors: May 16 Transplant: Jun 27 🍅 Harvest: Aug 22 – Oct 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 Pitkin County

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

Soil pH

Your soil pH (6.6โ€“8.3) is more alkaline than Collard Greens prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Pitkin County is excellent for Collard Greens โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Collard Greens.

How to Plant Collard Greens

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

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

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
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 1.9" 0" โ„๏ธ Dormant
May โ€” 2" 0" โ„๏ธ Dormant
Jun 3.5" 1.3" 2.2" ๐Ÿšฟ Regular watering
Jul 3.5" 1.4" 2.1" ๐Ÿšฟ Regular watering
Aug 3.5" 1.9" 1.6" ๐Ÿ’ง Light watering
Sep 3.5" 1.7" 1.8" ๐Ÿšฟ Regular watering
Oct โ€” 1.5" 0" โ„๏ธ Dormant
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Pitkin County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~748 GDD — county provides 954 GDD Good fit

Collard Greens Planting Timeline โ€” Pitkin County, CO

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 โ€“ May 19
Transplant Outdoors June 16 Jun 16 โ€“ Jun 30
Direct Sow June 9 Jun 9 โ€“ Jun 30
Harvest August 11 Aug 11 โ€“ Oct 13
Fall Sowing June 15 Jun 15 โ€“ Jun 29

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

55โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

83 days in Pitkin County

Growing Tips for Collard Greens in Pitkin County

Direct sow Collard Greens outdoors after June 16 in Pitkin County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Pitkin County is tight for Collard Greens (55.0-75.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Pitkin County, CO?

Pitkin County is in Zone 4a with an average last frost of June 16. Plan your Collard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pitkin County, CO?

Pitkin County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pitkin County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Pitkin County, CO. Local conditions may vary. Last updated: April 2026.