Blog

When to plant Corn in Knox County County,

In Zone 7a (Knox County County), direct-sow Corn between April 26 and May 17 for spring, after the April 19 last-frost mark.

When to Plant Corn in Knox County, KY

Corn
Knox County, Kentucky Zone 7a June

Your June gardening checklist

Here's what deserves your attention in Knox County, Kentucky this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 19
Avg. first frost October 21
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Bring in the corn

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in July — start thinking about
  • First harvests: corn

Instant PDF download. No spam, unsubscribe any time.

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.

Knox County, Kentucky is in USDA Zone 7a. The average last spring frost is April 19 and the first fall frost is October 21, giving you a growing season of approximately 185 days.

At an elevation of 2,802 feet, Knox County receives approximately 46.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Corn during the growing season.

Knox County, KY (Zone 7a) Moderate season
185 days
Last Spring Frost April 19
185 growing days
First Fall Frost October 21

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 9
Recommended (50%) ✓ Fits season (66 days to spare)
Transplant: Apr 19 🍅 Harvest: Jun 21 – Aug 16
Safe Start (90%) ✓ Fits season (58 days to spare)
Transplant: May 9 🍅 Harvest: Jul 11 – Sep 5

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 Knox County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Corn.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Corn.

How to Plant Corn

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

Succession Planting Corn

3
successive plantings in your 185-day season

Sow every 6.9 weeks. Last sowing by Jul 13 to harvest before frost.

Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 3.3" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.3" 0" ❄️ Dormant
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 3.2" 3.3" 🚿 Regular watering
Jun 6.5" 3.9" 2.6" 💧 Light watering
Jul 6.5" 4.8" 1.7" 💧 Light watering
Aug 6.5" 4.9" 1.6" 💧 Light watering
Sep 6.5" 3.2" 3.3" 🚿 Regular watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 3.8" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Knox 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 ~1,160 GDD — county provides 2,682 GDD Excellent fit

Corn Planting Timeline — Knox County, KY

Corn Planting Calendar

Activity When Date Range
Direct Sow April 26 Apr 26 – May 17
Harvest June 28 Jun 28 – Aug 23

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 · Natural rainfall sufficient

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

185 days in Knox County

Growing Tips for Corn in Knox County

Direct sow Corn outdoors after April 19 in Knox 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 Knox County, KY?

Knox County is in Zone 7a with an average last frost of April 19. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knox County, KY?

Knox County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 19 and first fall frost is October 21.

When should I plant Corn in Knox County County, ?

In Knox County County, , plant Corn after the last frost (around April 19) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Knox County County, for Corn?

Knox County County sits in USDA Zone 7a. Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Corn grow in Knox County County's climate?

Yes — Corn grows well in Knox County County's temperate climate. Knox County County averages a 185-day frost-free season, with last frost around April 19 and first frost around October 21.

🌱

Your Knox County Garden Planner — Free

A 22-page printable planner built for Knox 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Knox County, KY. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.