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When to Plant Sweet Corn in Middlesex County, CT

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.

Middlesex County, Connecticut is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 26, giving you a growing season of approximately 191 days.

At an elevation of 248 feet, Middlesex County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Sweet Corn during the growing season.

Middlesex County, CT (Zone 6b) Moderate season
191 days
Last Spring Frost April 18
191 growing days
First Fall Frost October 26

Middlesex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Transplant: Apr 11 🍅 Harvest: Jun 13 – Jul 25
Recommended (50%) ✓ Fits season (86 days to spare)
Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 1
Safe Start (90%) ✓ Fits season (78 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Aug 19

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 190 gal / 100 sq ft
Sweet Corn needs ~1,312 GDD — county provides 3,342 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Middlesex County, CT

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 25 Apr 25 โ€“ May 16
Harvest June 27 Jun 27 โ€“ Aug 8

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

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6b

Growing Season

191 days

Growing Tips for Middlesex 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sweet Corn in Middlesex County, CT?

Middlesex County is in Zone 6b with an average last frost of April 18. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Middlesex County, CT?

Middlesex County, Connecticut is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Middlesex County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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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 Middlesex County, CT. Local conditions may vary. Last updated: April 2026.