When to Plant Sweet Corn in San Patricio 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.
San Patricio County, Texas is in USDA Zone 9a. The average last spring frost is February 12 and the first fall frost is December 9, giving you a growing season of approximately 300 days.
At an elevation of 2,449 feet, San Patricio County receives approximately 54.7 inches of rainfall annually with predominantly loam soil. Summer highs average 100°F, 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.
San Patricio County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
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.
Plant Water Budget
Sweet Corn Planting Timeline — San Patricio County, TX
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | February 19 | Feb 19 – Mar 12 |
| Harvest | April 23 | Apr 23 – Jun 4 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Direct Sow |
| March | Direct Sow |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–90 days
Soil pH
6 – 7
USDA Zone
Zone 9a
Growing Season
300 days
Growing Tips for San Patricio 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
Level Up Your Garden
Sweet Corn in Other Locations
Frequently Asked Questions
When should I plant Sweet Corn in San Patricio County, TX?
San Patricio County is in Zone 9a with an average last frost of February 12. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Patricio County, TX?
San Patricio County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 12 and first fall frost is December 9.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help San Patricio County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.
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