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When to Plant Sweet Corn in Adair County, KY

Adair County, Kentucky Zone 7a May

Your May planting checklist for Adair County, Kentucky

A quick May briefing for Adair County, Kentucky gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 17
Avg. first frost October 21
Soil temp (4") 57°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
June prep starts now
  • First harvests: sweet corn

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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.

Adair County, Kentucky is in USDA Zone 7a. The average last spring frost is April 17 and the first fall frost is October 21, giving you a growing season of approximately 187 days.

At an elevation of 2,442 feet, Adair County receives approximately 42.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Sweet Corn during the growing season.

Adair County, KY (Zone 7a) Moderate season
187 days
Last Spring Frost April 17
187 growing days
First Fall Frost October 21

Adair County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Transplant: Apr 10 🍅 Harvest: Jun 12 – Jul 24
Recommended (50%) ✓ Fits season (82 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 19 – Jul 31
Safe Start (90%) ✓ Fits season (76 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Aug 17

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 Adair County

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Sweet Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Adair County 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 moderate (3.1%). Annual compost additions will help Sweet Corn.

How to Plant Sweet Corn

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

Succession Planting Sweet Corn

3
successive plantings in your 187-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 166 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 4.1" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 6.5" 3.7" 2.8" 💧 Light watering
May 6.5" 3" 3.5" 🚿 Regular watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 4.3" 2.2" 💧 Light watering
Sep 6.5" 2.9" 3.6" 🚿 Regular watering
Oct 6.5" 2.5" 4" 🚿 Regular watering
Nov 3.3" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Adair County). 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 ~1,256 GDD — county provides 3,132 GDD Excellent fit

Sweet Corn Planting Timeline — Adair County, KY

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 24 Apr 24 – May 15
Harvest June 26 Jun 26 – Aug 7

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

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: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

187 days in Adair County

Growing Tips for Sweet Corn in Adair County

Direct sow Sweet Corn outdoors after April 17 in Adair 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Adair County, KY?

Adair County is in Zone 7a with an average last frost of April 17. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adair County, KY?

Adair County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 17 and first fall frost is October 21.

🌱

Your Adair County Garden Planner — Free

A 24-page printable planner built for Adair County (Zone 7a). 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 Adair County, KY. 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.