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When to Plant Sweet Corn in Boyd County, KY

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.

Boyd County, Kentucky is in USDA Zone 6b. The average last spring frost is April 20 and the first fall frost is October 23, giving you a growing season of approximately 186 days.

At an elevation of 2,124 feet, Boyd County receives approximately 46.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Sweet Corn during the growing season.

Boyd County, KY (Zone 6b) Moderate season
186 days
Last Spring Frost April 20
186 growing days
First Fall Frost October 23

Boyd County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (82 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – Jul 27
Recommended (50%) ✓ Fits season (81 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 3
Safe Start (90%) ✓ Fits season (71 days to spare)
Transplant: May 10 🍅 Harvest: Jul 12 – Aug 23

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 Boyd County

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

Soil pH

Your soil pH (5.3โ€“6.5) is more acidic than Sweet Corn prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Corn.

Organic Matter

Organic matter is moderate (2.5%). 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 186-day season

Sow every 6.9 weeks. Last sowing by Jul 25 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 11 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 โ€” 3.4" 0" โ„๏ธ Dormant
Feb โ€” 3.6" 0" โ„๏ธ Dormant
Mar โ€” 4.6" 0" โ„๏ธ Dormant
Apr 6.5" 3.9" 2.6" ๐Ÿ’ง Light watering
May 6.5" 3.5" 3" ๐Ÿ’ง Light watering
Jun 6.5" 3.8" 2.7" ๐Ÿ’ง Light watering
Jul 6.5" 4.6" 1.9" ๐Ÿ’ง Light watering
Aug 6.5" 4.5" 2" ๐Ÿ’ง Light watering
Sep 6.5" 3.8" 2.7" ๐Ÿ’ง Light watering
Oct 6.5" 3.4" 3.1" ๐Ÿ’ง Light watering
Nov โ€” 3.3" 0" โ„๏ธ Dormant
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Boyd County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,369 GDD — county provides 3,394 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Boyd County, KY

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 27 Apr 27 โ€“ May 18
Harvest June 29 Jun 29 โ€“ Aug 10

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 Harvest
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 Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

186 days in Boyd County

Growing Tips for Sweet Corn in Boyd County

Direct sow Sweet Corn outdoors after April 20 in Boyd 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 Boyd County, KY?

Boyd County is in Zone 6b with an average last frost of April 20. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Boyd County, KY?

Boyd County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 20 and first fall frost is October 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Boyd County gardeners in Zone 6b 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 Boyd County, KY. Local conditions may vary. Last updated: April 2026.