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When to Plant Sweet Corn in Haskell County, OK

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.

Haskell County, Oklahoma is in USDA Zone 7a. The average last spring frost is March 28 and the first fall frost is November 3, giving you a growing season of approximately 220 days.

At an elevation of 691 feet, Haskell County receives approximately 29.2 inches of rainfall annually with predominantly loam soil. Summer highs average 91ยฐF, providing good warmth for Sweet Corn during the growing season.

Haskell County, OK (Zone 7a) Long season
220 days
Last Spring Frost March 28
220 growing days
First Fall Frost November 3

Haskell County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (115 days to spare)
Transplant: Mar 21 🍅 Harvest: May 23 – Jul 4
Recommended (50%) ✓ Fits season (115 days to spare)
Transplant: Mar 28 🍅 Harvest: May 30 – Jul 11
Safe Start (90%) ✓ Fits season (118 days to spare)
Transplant: Apr 14 🍅 Harvest: Jun 16 – Jul 28

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
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,040 gal / 100 sq ft
Drought risk

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

Sweet Corn needs ~1,369 GDD — county provides 4,015 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Haskell County, OK

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 4 Apr 4 โ€“ Apr 25
Harvest June 6 Jun 6 โ€“ Jul 18

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May โ€”
June Harvest
July Harvest
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€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

220 days

Growing Tips for Haskell County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sweet Corn in Haskell County, OK?

Haskell County is in Zone 7a with an average last frost of March 28. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Haskell County, OK?

Haskell County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is March 28 and first fall frost is November 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Haskell County gardeners in Zone 7a 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 Haskell County, OK. Local conditions may vary. Last updated: April 2026.