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When to Plant Corn in Sumner, NE

Corn
Sumner, NE Zone 5b June

This month in Sumner, NE

We've pulled the most time-sensitive tasks for Sumner, NE this June and put them front and centre. Tackle them in order.

Avg. last frost May 5
Avg. first frost October 3
Soil temp (4") 69°F
Watering Moderate
Pest pressure High
Daylight 14.9 hrs
Coming up in July — start thinking about
  • 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.

Sumner, Nebraska is in USDA Zone 5b. The average last spring frost is May 5 and the first fall frost is October 3, giving you a growing season of approximately 151 days.

At an elevation of 790 feet, Dawson County receives approximately 21.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Corn during the growing season.

Sumner, NE (Zone 5b) Moderate season
151 days
Last Spring Frost May 5
151 growing days
First Fall Frost October 3

Sumner Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 26
Recommended (50%) ✓ Fits season (32 days to spare)
Transplant: May 5 🍅 Harvest: Jul 7 – Sep 1
Safe Start (90%) ✓ Fits season (33 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Sep 13

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 Sumner

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

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Corn prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Dawson 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

2
successive plantings in your 151-day season

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

Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,441 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.6" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 6.5" 3.1" 3.4" 🚿 Regular watering
Jun 6.5" 3.3" 3.2" 💧 Light watering
Jul 6.5" 3" 3.5" 🚿 Regular watering
Aug 6.5" 2.9" 3.6" 🚿 Regular watering
Sep 6.5" 1.8" 4.7" 🚿 Regular watering
Oct 6.5" 1.3" 5.2" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Dawson 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 2,302 GDD Excellent fit

Corn Planting Timeline — Sumner, NE

Corn Planting Calendar

Activity When Date Range
Direct Sow May 12 May 12 – Jun 2
Harvest July 14 Jul 14 – Sep 8

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September Harvest
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: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

151 days in Dawson County

Growing Tips for Corn in Sumner

Direct sow Corn outdoors after May 05 in Dawson 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.

Dawson County receives only 22" of rain annually. Corn needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 →

🌱

Your Dawson County Garden Planner — Free

A 22-page printable planner built for Dawson County (Zone 5b). 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 Dawson County, NE. Local conditions may vary. Last updated: June 2026.