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When to Plant Spinach in Fairbanks North Star Borough, AK

Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.

Fairbanks North Star Borough, Alaska is in USDA Zone 2a. 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 69ยฐF, so choose short-season varieties of Spinach to ensure they mature before fall.

Fairbanks North Star Borough, AK (Zone 2a) 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 (16 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 17
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jun 19 – Aug 21
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Jul 4 – Sep 5

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.

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
Spinach needs ~74 GDD — county provides 203 GDD Excellent fit

Spinach Planting Timeline โ€” Fairbanks North Star Borough, AK

Spinach 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
Fall Sowing June 16 Jun 16 โ€“ Jun 30
Harvest June 19 Jun 19 โ€“ Aug 21

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

35โ€“50 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 2a

Growing Season

116 days

Growing Tips for Fairbanks North Star Borough

Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.

Companion Planting

Good Companions

Level Up Your Garden

๐ŸŒพ Save Your Own Spinach Seeds
Life Cycle Annual
Pollination Wind Pollinated
How to Collect Let plants bolt. Harvest seed stalks when seeds turn tan.
Storage Store airtight; viable 5 years at 35ยฐF, under 45% humidity.

Wind pollinated โ€” isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

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

Fairbanks North Star Borough is in Zone 2a with an average last frost of May 15. Plan your Spinach planting based on this frost date โ€” 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 2a. The average last spring frost is May 15 and first fall frost is September 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Fairbanks North Star Borough gardeners in Zone 2a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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.