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When to Plant Serviceberries in Fairbanks North Star Borough, AK

Fairbanks North Star Borough, Alaska Zone 3b May

What to do in May

Welcome to May in Zone 3b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 15
Avg. first frost September 8
Soil temp (4") 42°F
Watering Critical
Pest pressure Low
Daylight 18.2 hrs
Looking ahead to June
  • Transplants going out: serviceberries

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Serviceberries (saskatoons) are attractive native shrubs or small trees producing sweet, blueberry-like fruits. They have beautiful spring flowers and vibrant fall color.

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 Serviceberries 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) ✓ Fits season
Transplant: Jun 8
Recommended (50%) ✓ Fits season
Transplant: Jun 12
Safe Start (90%) ✓ Fits season
Transplant: Jun 27

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 Serviceberries's growing requirements.

Soil pH

Your soil pH (5.2–6.4) overlaps with Serviceberries's range (5.5–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Fairbanks North Star Borough is excellent for Serviceberries — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Serviceberries.

Organic Matter

Organic matter is excellent (6.7%) — Serviceberries will thrive.

How to Plant Serviceberries

120"
Between Plants
144"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Serviceberries

Serviceberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Serviceberries Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1" 0" ❄️ Dormant
May 4.3" 1.2" 3.1" 🚿 Regular watering
Jun 4.3" 2.4" 1.9" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 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.

Serviceberries 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.

Serviceberries needs ~1,597 GDD — county provides 203 GDD May not mature

Serviceberries Planting Timeline — Fairbanks North Star Borough, AK

Serviceberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 12 Jun 12 – Jun 26

· 120" apart · Rows 144" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 3b

📆 Growing Season

116 days in Fairbanks North Star Borough

Growing Tips for Serviceberries in Fairbanks North Star Borough

Direct sow Serviceberries outdoors after May 15 in Fairbanks North Star Borough when soil has warmed and frost danger has passed.

Your 116.0-day growing season in Fairbanks North Star Borough is tight for Serviceberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant in well-drained soil. Minimal pruning needed beyond removing dead wood. Protect fruit from birds with netting. Berries ripen in early summer and are excellent fresh or in pies.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Serviceberries in Fairbanks North Star Borough, AK?

Fairbanks North Star Borough is in Zone 3b with an average last frost of May 15. Plan your Serviceberries 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: May 2026.

Sources & credits

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