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When to Plant Corn in Kalawao County, HI

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Kalawao County, Hawaii is in USDA Zone 11a. The average last spring frost is January 1 and the first fall frost is December 31, giving you a growing season of approximately 364 days.

At an elevation of 402 feet, Kalawao County receives approximately 28.4 inches of rainfall annually with predominantly silty clay soil. Summer highs average 85ยฐF, providing good warmth for Corn during the growing season. Clay soil retains moisture well for Corn, but amend with compost to improve drainage and prevent root rot.

Kalawao County, HI (Zone 11a) Year-round
364 days
Last Spring Frost January 1
364 growing days
First Fall Frost December 31

Kalawao County Soil Profile

Soil Type

Silty Clay

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 12
Recommended (50%) ✓ Fits season (64 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 12
Safe Start (90%) ✓ Fits season (64 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 12

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
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 2,624 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Corn needs ~1,100 GDD — county provides 5,018 GDD Excellent fit

Corn Planting Timeline โ€” Kalawao County, HI

Corn Planting Calendar

Activity When Date Range
Direct Sow January 8 Jan 8 โ€“ Jan 29
Harvest March 12 Mar 12 โ€“ May 7

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 11a

Growing Season

364 days

Growing Tips for Kalawao County

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Level Up Your Garden

Frequently Asked Questions

When should I plant Corn in Kalawao County, HI?

Kalawao County is in Zone 11a with an average last frost of January 1. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kalawao County, HI?

Kalawao County, Hawaii is in USDA Hardiness Zone 11a. The average last spring frost is January 1 and first fall frost is December 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Kalawao County gardeners in Zone 11a 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 Kalawao County, HI. Local conditions may vary. Last updated: April 2026.