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When to Plant Sweet Corn in Uvalde County, TX

Uvalde County, Texas Zone 9a May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Uvalde County, Texas this May and put them front and centre. Tackle them in order.

Avg. last frost March 8
Avg. first frost November 14
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting sweet corn

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

To set up a strong June, finish these tasks
  • First harvests: sweet corn

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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.

Uvalde County, Texas is in USDA Zone 9a. The average last spring frost is March 8 and the first fall frost is November 14, giving you a growing season of approximately 251 days.

At an elevation of 2,809 feet, Uvalde County receives approximately 59.3 inches of rainfall annually with predominantly loam soil. Summer highs average 95°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.

Uvalde County, TX (Zone 9a) Long season
251 days
Last Spring Frost March 8
251 growing days
First Fall Frost November 14

Uvalde County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Transplant: Mar 1 🍅 Harvest: May 3 – Jun 14
Recommended (50%) ✓ Fits season (146 days to spare)
Transplant: Mar 8 🍅 Harvest: May 10 – Jun 21
Safe Start (90%) ✓ Fits season (131 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – Jul 27

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 Uvalde County

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

Soil pH

Your soil pH (6.8–7.6) is more alkaline than Sweet Corn prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Uvalde County is excellent for Sweet Corn — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). 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

4
successive plantings in your 251-day season

Sow every 6.9 weeks. Last sowing by Aug 16 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,361 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sweet Corn

Sweet Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Sweet Corn Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 6.5" 3.7" 2.8" 💧 Light watering
Apr 6.5" 6.3" 0.2" 💧 Light watering
May 6.5" 9.4" 0" ✅ Rainfall sufficient
Jun 6.5" 8.3" 0" ✅ Rainfall sufficient
Jul 6.5" 8.2" 0" ✅ Rainfall sufficient
Aug 6.5" 6.9" 0" ✅ Rainfall sufficient
Sep 6.5" 5.8" 0.7" 💧 Light watering
Oct 6.5" 4.1" 2.4" 💧 Light watering
Nov 6.5" 1.8" 4.7" 🚿 Regular watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Uvalde County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sweet Corn Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Sweet Corn needs ~1,594 GDD — county provides 5,333 GDD Excellent fit

Sweet Corn Planting Timeline — Uvalde County, TX

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 17 May 17 – Jun 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

251 days in Uvalde County

Growing Tips for Sweet Corn in Uvalde County

Direct sow Sweet Corn outdoors after March 08 in Uvalde 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Uvalde County, TX?

Uvalde County is in Zone 9a with an average last frost of March 8. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Uvalde County, TX?

Uvalde County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 8 and first fall frost is November 14.

🌱

Your Uvalde County Garden Planner — Free

A 24-page printable planner built for Uvalde County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Uvalde County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.