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When to plant Sweet Corn in Sumter County, AL

The best window to plant Sweet Corn in Sumter County, is March 28–April 18, when soil warms to 50°F. Last frost typically hits March 21; first frost November 8.

When to Plant Sweet Corn in Sumter County, AL

Sumter County, Alabama Zone 8b July

What to do in July

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 21
Avg. first frost November 8
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 13.9 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.

Sumter County, Alabama is in USDA Zone 8b. The average last spring frost is March 21 and the first fall frost is November 8, giving you a growing season of approximately 232 days.

At an elevation of 335 feet, Sumter County receives approximately 56.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°F, providing good warmth for Sweet Corn during the growing season. Clay soil retains moisture well for Sweet Corn, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Corn root diseases.

Sumter County, AL (Zone 8b) Long season
232 days
Last Spring Frost March 21
232 growing days
First Fall Frost November 8

Sumter County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Sweet Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Transplant: Mar 10 🍅 Harvest: May 12 – Jun 23
Recommended (50%) ✓ Fits season (127 days to spare)
Transplant: Mar 21 🍅 Harvest: May 23 – Jul 4
Safe Start (90%) ✓ Fits season (126 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Jul 23

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 Sumter County

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

Soil pH

Your soil pH (5.6–6.2) is more acidic than Sweet Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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

4
successive plantings in your 232-day season

Sow every 6.9 weeks. Last sowing by Aug 10 to harvest before frost.

Sweet Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 981 gal / 100 sq ft

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 5" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 6.5" 5.2" 1.3" 💧 Light watering
Apr 6.5" 4.7" 1.8" 💧 Light watering
May 6.5" 4.6" 1.9" 💧 Light watering
Jun 6.5" 4.9" 1.6" 💧 Light watering
Jul 6.5" 5.2" 1.3" 💧 Light watering
Aug 6.5" 5.9" 0.6" 💧 Light watering
Sep 6.5" 4" 2.5" 💧 Light watering
Oct 6.5" 3.7" 2.8" 💧 Light watering
Nov 6.5" 4" 2.5" 💧 Light watering
Dec 4.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Sumter 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 ~1,538 GDD — county provides 4,756 GDD Excellent fit

Sweet Corn Planting Timeline — Sumter County, AL

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow March 28 Mar 28 – Apr 18
Harvest May 30 May 30 – Jul 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

232 days in Sumter County

Growing Tips for Sweet Corn in Sumter County

Direct sow Sweet Corn outdoors after March 21 in Sumter County when soil has warmed and frost danger has passed.

With Sumter County's clay soil (32% clay), work in 3-4 inches of compost before planting Sweet Corn. Avoid tilling when soil is wet to prevent compaction.

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 Sumter County, AL?

Sumter County is in Zone 8b with an average last frost of March 21. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sumter County, AL?

Sumter County, Alabama is in USDA Hardiness Zone 8b. The average last spring frost is March 21 and first fall frost is November 8.

When should I plant Sweet Corn in Sumter County, AL?

In Sumter County, AL, plant Sweet Corn after the last frost (around March 21) and before the first frost (around November 8). Best results when soil holds above 50°F.

What growing zone is Sumter County, AL for Sweet Corn?

Sumter County sits in USDA Zone 8b. Sweet Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Sweet Corn grow in Sumter County's climate?

Yes — Sweet Corn grows well in Sumter County's temperate climate. Sumter County averages a 232-day frost-free season, with last frost around March 21 and first frost around November 8.

🌱

Your Sumter County Garden Planner — Free

A 22-page printable planner built for Sumter County (Zone 8b). 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 Sumter County, AL. 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.