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When to Plant Spinach in Ketchikan Gateway 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.

Ketchikan Gateway Borough, Alaska is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 19, giving you a growing season of approximately 177 days.

At an elevation of 1,212 feet, Ketchikan Gateway Borough receives approximately 57.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 65ยฐF, so choose short-season varieties of Spinach to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Spinach root diseases.

Ketchikan Gateway Borough, AK (Zone 7b) Moderate season
177 days
Last Spring Frost April 25
177 growing days
First Fall Frost October 19

Ketchikan Gateway Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: May 23 – Jul 25
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: May 30 – Aug 1
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 17 – Aug 19

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
1.4″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Spinach needs ~0 GDD — county provides 0 GDD May not mature

Spinach Planting Timeline โ€” Ketchikan Gateway Borough, AK

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 โ€“ Apr 4
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Direct Sow April 11 Apr 11 โ€“ May 2
Fall Sowing August 10 Aug 10 โ€“ Aug 24
Harvest May 30 May 30 โ€“ Aug 1

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow Harvest
June Harvest
July Harvest
August Fall Sowing 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 7b

Growing Season

177 days

Growing Tips for Ketchikan Gateway 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 Ketchikan Gateway Borough, AK?

Ketchikan Gateway Borough is in Zone 7b with an average last frost of April 25. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ketchikan Gateway Borough, AK?

Ketchikan Gateway Borough, Alaska is in USDA Hardiness Zone 7b. The average last spring frost is April 25 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ketchikan Gateway Borough gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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 Ketchikan Gateway Borough, AK. Local conditions may vary. Last updated: April 2026.