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When to plant Corn in Delphi, IN

Delphi gardeners should plant Corn between April 30 and May 21 in spring. With Delphi's Zone 6a climate (last frost April 23), Corn needs 60–100 days to mature — plant by July 8 for a full harvest.

When to Plant Corn in Delphi, IN

Corn
Carroll County, Indiana Zone 6a July

Your July game plan for Carroll County, Indiana

We've pulled the most time-sensitive tasks for Carroll County, Indiana this July and put them front and centre. Tackle them in order.

Avg. last frost April 23
Avg. first frost October 16
Soil temp (4") 75°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Basket week: corn

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

August prep starts now
  • 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.

Delphi, Indiana is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.

At an elevation of 1,252 feet, Carroll County receives approximately 41.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Corn to ensure they mature before fall.

Delphi, IN (Zone 6a) Moderate season
176 days
Last Spring Frost April 23
176 growing days
First Fall Frost October 16

Delphi Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 15
Recommended (50%) ✓ Fits season (57 days to spare)
Transplant: Apr 23 🍅 Harvest: Jun 25 – Aug 20
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: May 7 🍅 Harvest: Jul 9 – Sep 3

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 Delphi

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

Soil pH

Your soil pH (5.8–6.8) overlaps with Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Corn.

Organic Matter

Organic matter is excellent (4.1%) — Corn will thrive.

How to Plant Corn

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

Succession Planting Corn

3
successive plantings in your 176-day season

Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.

Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,496 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 2" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 6.5" 3.6" 2.9" 💧 Light watering
May 6.5" 5.4" 1.1" 💧 Light watering
Jun 6.5" 5.7" 0.8" 💧 Light watering
Jul 6.5" 4.4" 2.1" 💧 Light watering
Aug 6.5" 4.9" 1.6" 💧 Light watering
Sep 6.5" 3.4" 3.1" 💧 Light watering
Oct 6.5" 3.2" 3.3" 🚿 Regular watering
Nov 2.8" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Carroll 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 ~980 GDD — county provides 2,156 GDD Excellent fit

Corn Planting Timeline — Delphi, IN

Corn Planting Calendar

Activity When Date Range
Direct Sow April 30 Apr 30 – May 21
Harvest July 2 Jul 2 – Aug 27

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June
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 6a

📆 Growing Season

176 days in Carroll County

Growing Tips for Corn in Delphi

Direct sow Corn outdoors after April 23 in Carroll 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 →

When should I plant Corn in Delphi, IN?

In Delphi, IN, plant Corn after the last frost (around April 23) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Delphi, IN for Corn?

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

Can Corn grow in Delphi's climate?

Yes — Corn grows well in Delphi's temperate climate. Delphi averages a 176-day frost-free season, with last frost around April 23 and first frost around October 16.

🌱

Your Carroll County Garden Planner — Free

A 22-page printable planner built for Carroll 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 Carroll County, IN. Local conditions may vary. Last updated: July 2026.