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When to Plant Corn in Butler County, PA

Butler County, Pennsylvania Zone 6a May

Butler County, Pennsylvania gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Butler County, Pennsylvania this May and put them front and centre. Tackle them in order.

Avg. last frost April 29
Avg. first frost October 25
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Put corn seeds straight in the ground

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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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.

Butler County, Pennsylvania is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 25, giving you a growing season of approximately 179 days.

At an elevation of 1,098 feet, Butler County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Corn during the growing season.

Butler County, PA (Zone 6a) Moderate season
179 days
Last Spring Frost April 29
179 growing days
First Fall Frost October 25

Butler County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 24 🍅 Harvest: Jun 26 – Aug 21
Recommended (50%) ✓ Fits season (60 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 26
Safe Start (90%) ✓ Fits season (55 days to spare)
Transplant: May 16 🍅 Harvest: Jul 18 – Sep 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 Butler County

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

Soil pH

Your soil pH (5.1–6.3) is more acidic than Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.5%). 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 179-day season

Sow every 6.9 weeks. Last sowing by Jul 17 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 865 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 3.1" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 6.5" 3.1" 3.4" 🚿 Regular watering
May 6.5" 4" 2.5" 💧 Light watering
Jun 6.5" 3.8" 2.7" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 3.3" 3.2" 💧 Light watering
Sep 6.5" 3.1" 3.4" 🚿 Regular watering
Oct 6.5" 3.3" 3.2" 💧 Light watering
Nov 3.1" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Butler 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 ~1,220 GDD — county provides 2,729 GDD Excellent fit

Corn Planting Timeline — Butler County, PA

Corn Planting Calendar

Activity When Date Range
Direct Sow May 6 May 6 – May 27
Harvest July 8 Jul 8 – Sep 2

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6a

📆 Growing Season

179 days in Butler County

Growing Tips for Corn in Butler County

Direct sow Corn outdoors after April 29 in Butler 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 Butler County, PA?

Butler County is in Zone 6a with an average last frost of April 29. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Butler County, PA?

Butler County, Pennsylvania is in USDA Hardiness Zone 6a. The average last spring frost is April 29 and first fall frost is October 25.

🌱

Your Butler County Garden Planner — Free

A 24-page printable planner built for Butler County (Zone 6a). 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 Butler County, PA. 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.