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When to Plant Sweet Corn in Grainger County, TN

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.

Grainger County, Tennessee is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 3,009 feet, Grainger County receives approximately 49.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92ยฐF, providing good warmth for Sweet Corn during the growing season.

Grainger County, TN (Zone 7a) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Grainger County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Transplant: Apr 8 🍅 Harvest: Jun 10 – Jul 22
Recommended (50%) ✓ Fits season (85 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29
Safe Start (90%) ✓ Fits season (80 days to spare)
Transplant: May 2 🍅 Harvest: Jul 4 – Aug 15

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 Grainger County

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

Soil pH

Your soil pH (5.5โ€“6.8) overlaps with Sweet Corn's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Grainger County is excellent for Sweet Corn โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). 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 190-day season

Sow every 6.9 weeks. Last sowing by Jul 24 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.1″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 686 gal / 100 sq ft
Sweet Corn needs ~1,425 GDD — county provides 3,610 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Grainger County, TN

Sweet Corn Planting Calendar

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

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

190 days in Grainger County

Growing Tips for Sweet Corn in Grainger County

Direct sow Sweet Corn outdoors after April 15 in Grainger 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sweet Corn in Grainger County, TN?

Grainger County is in Zone 7a with an average last frost of April 15. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grainger County, TN?

Grainger County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grainger County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Grainger County, TN. Local conditions may vary. Last updated: April 2026.