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When to Plant Sweet Corn in Kodiak Island Borough, AK

Kodiak Island Borough, Alaska Zone 7b May

Your May planting checklist for Kodiak Island Borough, Alaska

Each item below is timed to Kodiak Island Borough, Alaska's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 13
Avg. first frost September 29
Soil temp (4") 58°F
Watering High
Pest pressure Low
Daylight 16.3 hrs
  1. Outdoor sowing time: sweet corn

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.

Kodiak Island Borough, Alaska is in USDA Zone 7b. 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 Sweet Corn to ensure they mature before fall.

Kodiak Island Borough, AK (Zone 7b) 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 (42 days to spare)
Transplant: May 2 🍅 Harvest: Jul 4 – Aug 15
Recommended (50%) ✓ Fits season (34 days to spare)
Transplant: May 13 🍅 Harvest: Jul 15 – Aug 26
Safe Start (90%) ✓ Fits season (44 days to spare)
Transplant: May 25 🍅 Harvest: Jul 27 – Sep 7

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 Kodiak Island Borough

How your county's soil matches Sweet Corn's growing requirements.

Soil pH

Your soil pH (5.1–6.5) is more acidic than Sweet Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Kodiak Island Borough is excellent for Sweet Corn — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sweet Corn.

Organic Matter

Organic matter is excellent (5.3%) — Sweet Corn will thrive.

How to Plant Sweet Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Sweet Corn

2
successive plantings in your 139-day season

Sow every 6.9 weeks. Last sowing by Jul 01 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 264 gal / 100 sq ft

Monthly Watering Guide for Sweet Corn

Sweet Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Sweet Corn Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 0.8" 0" ❄️ Dormant
May 6.5" 1.4" 5.1" 🚿 Regular watering
Jun 6.5" 2.4" 4.1" 🚿 Regular watering
Jul 6.5" 3.2" 3.3" 🚿 Regular watering
Aug 6.5" 4" 2.5" 💧 Light watering
Sep 6.5" 5" 1.5" 💧 Light watering
Oct 3.6" 0" ❄️ Dormant
Nov 1.9" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Kodiak Island Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sweet Corn 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.

Sweet Corn needs ~0 GDD — county provides 0 GDD May not mature

Sweet Corn Planting Timeline — Kodiak Island Borough, AK

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow May 20 May 20 – Jun 10
Harvest July 22 Jul 22 – Sep 2

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

139 days in Kodiak Island Borough

Growing Tips for Sweet Corn in Kodiak Island Borough

Direct sow Sweet Corn outdoors after May 13 in Kodiak Island Borough when soil has warmed and frost danger has passed.

Common pests for Sweet Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Kodiak Island Borough, AK?

Kodiak Island Borough is in Zone 7b with an average last frost of May 13. Plan your Sweet Corn 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 7b. The average last spring frost is May 13 and first fall frost is September 29.

🌱

Your Kodiak Island Borough Garden Planner — Free

A 24-page printable planner built for Kodiak Island Borough (Zone 7b). 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 Kodiak Island 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.