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When to plant Corn in Washington County, IN

The best window to plant Corn in Washington County, is April 19–May 10, when soil warms to 50°F. Last frost typically hits April 12; first frost October 20.

When to Plant Corn in Washington County, IN

Corn
Washington County, Indiana Zone 6b June

Top priorities for Washington County, Indiana gardeners in June

June is a pivotal month for Washington County, Indiana gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 12
Avg. first frost October 20
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Pick corn

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong July, finish these tasks
  • 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.

Washington County, Indiana is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 20, giving you a growing season of approximately 191 days.

At an elevation of 540 feet, Washington County receives approximately 32.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Corn during the growing season.

Washington County, IN (Zone 6b) Moderate season
191 days
Last Spring Frost April 12
191 growing days
First Fall Frost October 20

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.1

Drainage

Well Drained

Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Transplant: Apr 8 🍅 Harvest: Jun 10 – Aug 5
Recommended (50%) ✓ Fits season (72 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 9
Safe Start (90%) ✓ Fits season (64 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 2 – Aug 27

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 Washington County

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

Soil pH

Your soil pH (6.3–7.1) overlaps with Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Corn will thrive.

How to Plant Corn

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

Succession Planting Corn

3
successive plantings in your 191-day season

Sow every 6.9 weeks. Last sowing by Jul 12 to harvest before frost.

Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,331 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 1.5" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 6.5" 3" 3.5" 🚿 Regular watering
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 3.8" 2.7" 💧 Light watering
Jul 6.5" 3.9" 2.6" 💧 Light watering
Aug 6.5" 3.4" 3.1" 💧 Light watering
Sep 6.5" 3.2" 3.3" 🚿 Regular watering
Oct 6.5" 2.6" 3.9" 🚿 Regular watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Washington 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 2,769 GDD Excellent fit

Corn Planting Timeline — Washington County, IN

Corn Planting Calendar

Activity When Date Range
Direct Sow April 19 Apr 19 – May 10
Harvest June 21 Jun 21 – Aug 16

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 · 2-3 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

191 days in Washington County

Growing Tips for Corn in Washington County

Direct sow Corn outdoors after April 12 in Washington 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 Washington County, IN?

Washington County is in Zone 6b with an average last frost of April 12. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, IN?

Washington County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 20.

When should I plant Corn in Washington County, IN?

In Washington County, IN, plant Corn after the last frost (around April 12) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Washington County, IN for Corn?

Washington County sits in USDA Zone 6b. Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Corn grow in Washington County's climate?

Yes — Corn grows well in Washington County's temperate climate. Washington County averages a 191-day frost-free season, with last frost around April 12 and first frost around October 20.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 6b). 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 Washington County, IN. 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.