When to Plant Sweet Corn in Marshall County, AL
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.
Marshall County, Alabama is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is October 31, giving you a growing season of approximately 209 days.
At an elevation of 159 feet, Marshall County receives approximately 60.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89°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.
Marshall County Soil Profile
Soil Type
Clay Loam
Soil pH
5.5-6.6
Drainage
Well Drained
Plant Planting Risk Windows
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 Marshall 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 clay loam soil in Marshall 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
Succession Planting Sweet Corn
Sow every 6.9 weeks. Last sowing by Aug 02 to harvest before frost.
Plant Water Budget
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 | — | 5.3" | 0" | ❄️ Dormant |
| Mar | — | 5.4" | 0" | ❄️ Dormant |
| Apr | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| May | 6.5" | 4.8" | 1.7" | 💧 Light watering |
| Jun | 6.5" | 5" | 1.5" | 💧 Light watering |
| Jul | 6.5" | 6.7" | 0" | ✅ Rainfall sufficient |
| Aug | 6.5" | 5.4" | 1.1" | 💧 Light watering |
| Sep | 6.5" | 4.2" | 2.3" | 💧 Light watering |
| Oct | 6.5" | 4.2" | 2.3" | 💧 Light watering |
| Nov | — | 5.1" | 0" | ❄️ Dormant |
| Dec | — | 4.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Marshall 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 Planting Timeline — Marshall County, AL
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | June 14 | Jun 14 – Jul 26 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
209 days in Marshall County
Growing Tips for Sweet Corn in Marshall County
Direct sow Sweet Corn outdoors after April 05 in Marshall County when soil has warmed and frost danger has passed.
With Marshall County's clay soil (34% 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
Check more plant combinations with our Companion Planting Checker →
Sweet Corn in Other Locations
Frequently Asked Questions
When should I plant Sweet Corn in Marshall County, AL?
Marshall County is in Zone 7a with an average last frost of April 5. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, AL?
Marshall County, Alabama is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is October 31.
Plan Your Garden with Confidence
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