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When to plant Sweet Corn in Jasper County, MO

Aim to plant Sweet Corn in Jasper County on or after April 16; the window stays open through May 7. Jasper County's 200-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Sweet Corn in Jasper County, MO

Jasper County, Missouri Zone 7a July

Jasper County, Missouri gardeners: here's your July plan

Welcome to July in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 9
Avg. first frost October 26
Soil temp (4") 80°F
Watering Moderate
Pest pressure High
Daylight 14.3 hrs

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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.

Jasper County, Missouri is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 26, giving you a growing season of approximately 200 days.

At an elevation of 1,156 feet, Jasper County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sweet Corn during the growing season.

Jasper County, MO (Zone 7a) Long season
200 days
Last Spring Frost April 9
200 growing days
First Fall Frost October 26

Jasper County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Sweet Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (95 days to spare)
Transplant: Apr 3 🍅 Harvest: Jun 5 – Jul 17
Recommended (50%) ✓ Fits season (95 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Jul 23
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 23 – Aug 4

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 Jasper County

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

Soil pH

Your soil pH (5.5–6.6) overlaps with Sweet Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Sweet Corn.

How to Plant Sweet Corn

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

Succession Planting Sweet Corn

3
successive plantings in your 200-day season

Sow every 6.9 weeks. Last sowing by Jul 28 to harvest before frost.

Sweet Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,822 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Sweet Corn

Sweet 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 Sweet Corn Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 6.5" 2.9" 3.6" 🚿 Regular watering
May 6.5" 3.5" 3" 💧 Light watering
Jun 6.5" 4.3" 2.2" 💧 Light watering
Jul 6.5" 3.1" 3.4" 🚿 Regular watering
Aug 6.5" 3.6" 2.9" 💧 Light watering
Sep 6.5" 2.5" 4" 🚿 Regular watering
Oct 6.5" 2.4" 4.1" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Sweet 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.

Sweet Corn needs ~1,088 GDD — county provides 2,900 GDD Excellent fit

Sweet Corn Planting Timeline — Jasper County, MO

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 16 Apr 16 – May 7
Harvest June 18 Jun 18 – Jul 30

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
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

200 days in Jasper County

Growing Tips for Sweet Corn in Jasper County

Direct sow Sweet Corn outdoors after April 09 in Jasper County when soil has warmed and frost danger has passed.

Common pests for Sweet 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 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 Jasper County, MO?

Jasper County is in Zone 7a with an average last frost of April 9. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jasper County, MO?

Jasper County, Missouri is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 26.

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

In Jasper County, MO, plant Sweet Corn after the last frost (around April 9) and before the first frost (around October 26). Best results when soil holds above 50°F.

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

Jasper County sits in USDA Zone 7a. Sweet Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Sweet Corn grow in Jasper County's climate?

Yes — Sweet Corn grows well in Jasper County's temperate climate. Jasper County averages a 200-day frost-free season, with last frost around April 9 and first frost around October 26.

🌱

Your Jasper County Garden Planner — Free

A 22-page printable planner built for Jasper County (Zone 7a). 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 Jasper County, MO. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.