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When to Plant Collard Greens in Anchorage Municipality, AK

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.

Anchorage Municipality, Alaska is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 19, giving you a growing season of approximately 127 days.

At an elevation of 2,537 feet, Anchorage Municipality receives approximately 20.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 71ยฐF, so choose short-season varieties of Collard Greens to ensure they mature before fall.

Anchorage Municipality, AK (Zone 4b) Short season
127 days
Last Spring Frost May 15
127 growing days
First Fall Frost September 19

Anchorage Municipality Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 23 Transplant: May 4 🍅 Harvest: Jun 29 – Aug 31
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 11
Safe Start (90%) ✓ Fits season (1 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 29

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 Anchorage Municipality

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

Soil pH

Your soil pH (4.9โ€“6.5) is more acidic than Collard Greens prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Collard Greens.

Organic Matter

Organic matter is excellent (5.2%) โ€” Collard Greens will thrive.

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.

Succession Planting Collard Greens

2
successive plantings in your 127-day season

Sow every 6.3 weeks. Last sowing by Jul 06 to harvest before frost.

For a dedicated fall crop, sow by Jun 27.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/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 โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 0.8" 0" โ„๏ธ Dormant
Apr โ€” 0.6" 0" โ„๏ธ Dormant
May 3.5" 0.9" 2.6" ๐Ÿšฟ Regular watering
Jun 3.5" 1.5" 2" ๐Ÿšฟ Regular watering
Jul 3.5" 2.6" 0.9" ๐Ÿ’ง Light watering
Aug 3.5" 3.3" 0.2" ๐Ÿ’ง Light watering
Sep 3.5" 3.2" 0.3" ๐Ÿ’ง Light watering
Oct โ€” 2.4" 0" โ„๏ธ Dormant
Nov โ€” 1.7" 0" โ„๏ธ Dormant
Dec โ€” 1.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Anchorage Municipality). 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 ~211 GDD — county provides 412 GDD Excellent fit

Collard Greens Planting Timeline โ€” Anchorage Municipality, AK

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 โ€“ Apr 17
Transplant Outdoors May 15 May 15 โ€“ May 29
Direct Sow May 8 May 8 โ€“ May 29
Harvest July 10 Jul 10 โ€“ Sep 11
Fall Sowing June 27 Jun 27 โ€“ Jul 11

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

Month-by-Month Timeline

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

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

127 days in Anchorage Municipality

Growing Tips for Collard Greens in Anchorage Municipality

Direct sow Collard Greens outdoors after May 15 in Anchorage Municipality 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 Anchorage Municipality, AK?

Anchorage Municipality is in Zone 4b with an average last frost of May 15. Plan your Collard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Anchorage Municipality, AK?

Anchorage Municipality, Alaska is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 19.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Anchorage Municipality, AK. Local conditions may vary. Last updated: April 2026.