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When to Plant Sweet Corn in Stephens 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.

Stephens County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 979 feet, Stephens County receives approximately 26.1 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Sweet Corn during the growing season.

Stephens County, OK (Zone 7b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Stephens County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (105 days to spare)
Transplant: Mar 28 🍅 Harvest: May 30 – Jul 11
Recommended (50%) ✓ Fits season (104 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 8 – Jul 20
Safe Start (90%) ✓ Fits season (113 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29

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 Stephens County

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

Soil pH

Your soil pH (6.3โ€“7.6) overlaps with Sweet Corn's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Stephens County is excellent for Sweet Corn โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” Sweet Corn will thrive.

How to Plant Sweet Corn

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

Succession Planting Sweet Corn

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 2,177 gal / 100 sq ft
Drought risk

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

Sweet Corn needs ~1,312 GDD — county provides 3,657 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Stephens County, OK

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest June 15 Jun 15 โ€“ Jul 27

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 Direct Sow
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

209 days in Stephens County

Growing Tips for Sweet Corn in Stephens County

Direct sow Sweet Corn outdoors after April 06 in Stephens County 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

Level Up Your Garden

Frequently Asked Questions

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

Stephens County is in Zone 7b with an average last frost of April 6. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Stephens County, OK?

Stephens County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

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