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When to plant Sweet Corn in Randolph County, MO

Randolph County gardeners should plant Sweet Corn between April 22 and May 13 in spring. With Randolph County's Zone 6a climate (last frost April 15), Sweet Corn needs 60–90 days to mature — plant by July 20 for a full harvest.

When to Plant Sweet Corn in Randolph County, MO

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.

Randolph County, Missouri is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.

At an elevation of 1,243 feet, Randolph County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Sweet Corn during the growing season.

Randolph County, MO (Zone 6a) Moderate season
186 days
Last Spring Frost April 15
186 growing days
First Fall Frost October 18

Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.9

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 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Randolph County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sweet Corn Planting Timeline — Randolph County, MO

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 22 Apr 22 – May 13
Harvest June 24 Jun 24 – Aug 5

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

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

186 days in Randolph County

Growing Tips for Randolph 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 Randolph County, MO?

Randolph County is in Zone 6a with an average last frost of April 15. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, MO?

Randolph County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 18.

When should I plant Sweet Corn in Randolph County, MO?

In Randolph County, MO, plant Sweet Corn after the last frost (around April 15) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Randolph County, MO for Sweet Corn?

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

Can Sweet Corn grow in Randolph County's climate?

Yes — Sweet Corn grows well in Randolph County's temperate climate. Randolph County averages a 186-day frost-free season, with last frost around April 15 and first frost around October 18.

🌱

Your Randolph County Garden Planner — Free

A 22-page printable planner built for Randolph 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 Randolph County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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