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When to Plant Corn in Stephens County, OK

Stephens County, Oklahoma Zone 8a May

Stephens County, Oklahoma gardeners: here's your May plan

Your Stephens County, Oklahoma garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 6
Avg. first frost November 1
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
Before June arrives, get these ready
  • First harvests: corn

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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.

Stephens County, Oklahoma is in USDA Zone 8a. 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 90°F, providing good warmth for Corn during the growing season.

Stephens County, OK (Zone 8a) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1
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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 (91 days to spare)
Transplant: Mar 28 🍅 Harvest: May 30 – Jul 25
Recommended (50%) ✓ Fits season (90 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 8 – Aug 3
Safe Start (90%) ✓ Fits season (99 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.

Soil Compatibility in Stephens County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Corn will thrive.

How to Plant Corn

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

Succession Planting Corn

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Jul 24 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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Corn

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 Corn Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 6.5" 2.7" 3.8" 🚿 Regular watering
May 6.5" 3.9" 2.6" 💧 Light watering
Jun 6.5" 4.3" 2.2" 💧 Light watering
Jul 6.5" 3" 3.5" 🚿 Regular watering
Aug 6.5" 3.5" 3" 💧 Light watering
Sep 6.5" 2.4" 4.1" 🚿 Regular watering
Oct 6.5" 1.9" 4.6" 🚿 Regular watering
Nov 6.5" 0.8" 5.7" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Stephens County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

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.

Corn needs ~1,400 GDD — county provides 3,657 GDD Excellent fit

Corn Planting Timeline — Stephens County, OK

Corn Planting Calendar

Activity When Date Range
Direct Sow April 13 Apr 13 – May 4
Harvest June 15 Jun 15 – Aug 10

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

209 days in Stephens County

Growing Tips for Corn in Stephens County

Direct sow Corn outdoors after April 06 in Stephens County when soil has warmed and frost danger has passed.

Common pests for 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 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Stephens County, OK?

Stephens County is in Zone 8a with an average last frost of April 6. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Stephens County, OK?

Stephens County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is November 1.

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Your Stephens County Garden Planner — Free

A 24-page printable planner built for Stephens County (Zone 8a). 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 Stephens County, OK. 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.