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When to Plant Sweet Corn in Zapata 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.

Zapata County, Texas is in USDA Zone 9a. The average last spring frost is February 3 and the first fall frost is December 14, giving you a growing season of approximately 314 days.

At an elevation of 3,340 feet, Zapata County receives approximately 60.6 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, so Sweet Corn may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Corn root diseases.

Zapata County, TX (Zone 9a) Year-round
314 days
Last Spring Frost February 3
314 growing days
First Fall Frost December 14

Zapata County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (218 days to spare)
Transplant: Jan 17 🍅 Harvest: Mar 21 – May 2
Recommended (50%) ✓ Fits season (209 days to spare)
Transplant: Feb 3 🍅 Harvest: Apr 7 – May 19
Safe Start (90%) ✓ Fits season (195 days to spare)
Transplant: Feb 27 🍅 Harvest: May 1 – Jun 12

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 538 gal / 100 sq ft
Sweet Corn needs ~2,044 GDD — county provides 8,583 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Zapata County, TX

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow February 10 Feb 10 โ€“ Mar 3
Harvest April 14 Apr 14 โ€“ May 26

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Direct Sow
March Direct Sow
April Harvest
May Harvest
June โ€”
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 9a

Growing Season

314 days

Growing Tips for Zapata 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 Zapata County, TX?

Zapata County is in Zone 9a with an average last frost of February 3. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Zapata County, TX?

Zapata County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 3 and first fall frost is December 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Zapata County gardeners in Zone 9a 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 Zapata County, TX. Local conditions may vary. Last updated: April 2026.