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When to Plant Watermelon in Kodiak Island Borough, AK

Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.

Kodiak Island Borough, Alaska is in USDA Zone 6a. The average last spring frost is May 13 and the first fall frost is September 29, giving you a growing season of approximately 139 days.

At an elevation of 2,281 feet, Kodiak Island Borough receives approximately 27.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 60ยฐF, so choose short-season varieties of Watermelon to ensure they mature before fall.

Kodiak Island Borough, AK (Zone 6a) Short season
139 days
Last Spring Frost May 13
139 growing days
First Fall Frost September 29

Kodiak Island Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Jul 25 – Sep 12
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Apr 8 Transplant: May 27 🍅 Harvest: Aug 5 – Sep 23
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 20 Transplant: Jun 8 🍅 Harvest: Aug 17 – Oct 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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Watermelon needs ~0 GDD — county provides 0 GDD May not mature

Watermelon Planting Timeline โ€” Kodiak Island Borough, AK

Watermelon Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 โ€“ Apr 22
Transplant Outdoors May 27 May 27 โ€“ Jun 10
Direct Sow May 20 May 20 โ€“ Jun 10
Harvest August 5 Aug 5 โ€“ Sep 23

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

139 days

Growing Tips for Kodiak Island Borough

Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Watermelon in Kodiak Island Borough, AK?

Kodiak Island Borough is in Zone 6a with an average last frost of May 13. Plan your Watermelon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kodiak Island Borough, AK?

Kodiak Island Borough, Alaska is in USDA Hardiness Zone 6a. The average last spring frost is May 13 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Kodiak Island Borough gardeners in Zone 6a 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 Kodiak Island Borough, AK. Local conditions may vary. Last updated: April 2026.