When to Plant Onion in Kodiak Island Borough, AK
Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.
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 60°F, so choose short-season varieties of Onion to ensure they mature before fall.
Kodiak Island Borough Soil Profile
Soil Type
Silt Loam
Soil pH
5.1-6.5
Drainage
Well Drained
Plant Planting Risk Windows
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
Onion Planting Timeline — Kodiak Island Borough, AK
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | April 29 | Apr 29 – May 20 |
| Fall Sowing | July 21 | Jul 21 – Aug 4 |
| Harvest | August 12 | Aug 12 – Sep 30 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
6 – 7
USDA Zone
Zone 6a
Growing Season
139 days
Growing Tips for Kodiak Island Borough
Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Kodiak Island Borough, AK?
Kodiak Island Borough is in Zone 6a with an average last frost of May 13. Plan your Onion planting based on this frost date — 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.
Plan Your Garden with Confidence
Get our free Garden Planner — 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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