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When to Plant Collard Greens in Fairbanks North Star Borough, AK

Fairbanks North Star Borough, Alaska Zone 3b April

Fairbanks North Star Borough, Alaska gardeners: here's your April plan

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Fairbanks North Star Borough, Alaska.

Avg. last frost May 15
Avg. first frost September 8
Soil temp (4") 30°F
Watering None
Pest pressure Low
Daylight 14.8 hrs
May prep starts now
  • Transplants going out: collard greens
  • Direct-sowing: 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.

Fairbanks North Star Borough, Alaska is in USDA Zone 3b. The average last spring frost is May 15 and the first fall frost is September 8, giving you a growing season of approximately 116 days.

At an elevation of 2,540 feet, Fairbanks North Star Borough receives approximately 29.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 69°F, so choose short-season varieties of Collard Greens to ensure they mature before fall.

Fairbanks North Star Borough, AK (Zone 3b) Short season
116 days
Last Spring Frost May 15
116 growing days
First Fall Frost September 8

Fairbanks North Star Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jul 6 – Sep 7
Recommended (50%) ✗ May not fit
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 11
Safe Start (90%) ✗ May not fit
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Jul 25 – Sep 26

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 Fairbanks North Star Borough

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

Soil pH

Your soil pH (5.2–6.4) is more acidic than Collard Greens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Fairbanks North Star Borough 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 (6.7%) — 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 116-day season

Sow every 6.3 weeks. Last sowing by Jun 25 to harvest before frost.

For a dedicated fall crop, sow by Jun 16.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.1″/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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1" 0" ❄️ Dormant
May 3.5" 1.2" 2.3" 🚿 Regular watering
Jun 3.5" 2.4" 1.1" 💧 Light watering
Jul 3.5" 3.3" 0.2" 💧 Light watering
Aug 3.5" 4.1" 0" ✅ Rainfall sufficient
Sep 3.5" 5.3" 0" ✅ Rainfall sufficient
Oct 3.8" 0" ❄️ Dormant
Nov 2.2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Fairbanks North Star Borough). 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 ~114 GDD — county provides 203 GDD Excellent fit

Collard Greens Planting Timeline — Fairbanks North Star Borough, AK

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 10 Jul 10 – Sep 11
Fall Sowing June 16 Jun 16 – Jun 30

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Fall Sowing
July Harvest
August Harvest
September Harvest
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: too_acidic

🗺️ USDA Zone

Zone 3b

📆 Growing Season

116 days in Fairbanks North Star Borough

Growing Tips for Collard Greens in Fairbanks North Star Borough

Direct sow Collard Greens outdoors after May 15 in Fairbanks North Star Borough 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 Fairbanks North Star Borough, AK?

Fairbanks North Star Borough is in Zone 3b with an average last frost of May 15. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fairbanks North Star Borough, AK?

Fairbanks North Star Borough, Alaska is in USDA Hardiness Zone 3b. The average last spring frost is May 15 and first fall frost is September 8.

🌱

Your Fairbanks North Star Borough Garden Planner — Free

A 24-page printable planner built for Fairbanks North Star Borough (Zone 3b). 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 Fairbanks North Star Borough, AK. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.