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When to Plant Sweet Corn in Knox County, NE

Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.

Knox County, Nebraska is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 6, giving you a growing season of approximately 159 days.

At an elevation of 723 feet, Knox County receives approximately 32.8 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Sweet Corn to ensure they mature before fall.

Knox County, NE (Zone 4b) Moderate season
159 days
Last Spring Frost April 30
159 growing days
First Fall Frost October 6

Knox County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Monthly Watering Guide for Sweet Corn

Sweet Corn needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sweet Corn Needs Rainfall You Supplement Action
Jan โ€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 2.3" 0" โ„๏ธ Dormant
Apr 4.3" 3" 1.3" ๐Ÿ’ง Light watering
May 4.3" 4.7" 0" โœ… Rainfall sufficient
Jun 4.3" 4.8" 0" โœ… Rainfall sufficient
Jul 4.3" 4.3" 0" โœ… Rainfall sufficient
Aug 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Sep 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Oct 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Knox County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sweet Corn Planting Timeline โ€” Knox County, NE

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow May 14 May 14 โ€“ Jun 4
Harvest July 16 Jul 16 โ€“ Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

159 days in Knox County

Growing Tips for Knox County

Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Knox County, NE?

Knox County is in Zone 4b with an average last frost of April 30. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Knox County, NE?

Knox County, Nebraska is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Knox County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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