When to Plant Sweet Corn in Rock 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.
Rock County, Nebraska is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 6, giving you a growing season of approximately 149 days.
At an elevation of 1,012 feet, Rock County receives approximately 32.4 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Sweet Corn to ensure they mature before fall.
Rock County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.3
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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 3.8" | 0" | ❄️ Dormant |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Aug | 4.3" | 4" | 0.3" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Nov | — | 1.1" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Rock County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Corn Planting Timeline — Rock County, NE
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 24 | May 24 – Jun 14 |
| Harvest | July 26 | Jul 26 – Sep 6 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
Moderate — regular watering
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
149 days in Rock County
Growing Tips for Rock 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
Check more plant combinations with our Companion Planting Checker →
Sweet Corn in Other Locations
Frequently Asked Questions
When should I plant Sweet Corn in Rock County, NE?
Rock County is in Zone 4b with an average last frost of May 10. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Rock County, NE?
Rock County, Nebraska is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 6.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Rock County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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