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When to Plant Sweet Corn in Collin County, TX

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.

Collin County, Texas is in USDA Zone 8a. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94ยฐF, 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.

Collin County, TX (Zone 8a) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20

Collin County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (149 days to spare)
Transplant: Mar 2 🍅 Harvest: May 4 – Jun 15
Recommended (50%) ✓ Fits season (150 days to spare)
Transplant: Mar 10 🍅 Harvest: May 12 – Jun 23
Safe Start (90%) ✓ Fits season (135 days to spare)
Transplant: Apr 11 🍅 Harvest: Jun 13 – Jul 25

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Sweet Corn needs ~1,538 GDD — county provides 5,227 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Collin County, TX

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow March 17 Mar 17 โ€“ Apr 7
Harvest May 19 May 19 โ€“ Jun 30

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April Direct Sow
May Harvest
June Harvest
July โ€”
August โ€”
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 8a

Growing Season

255 days

Growing Tips for Collin 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 Collin County, TX?

Collin County is in Zone 8a with an average last frost of March 10. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Collin County, TX?

Collin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 10 and first fall frost is November 20.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Collin County gardeners in Zone 8a 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 Collin County, TX. Local conditions may vary. Last updated: April 2026.