When to Plant Sweet Corn in Caldwell County, TX
Caldwell County, Texas gardeners: here's your May plan
Here's what deserves your attention in Caldwell County, Texas this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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Bring in the sweet corn
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Looking ahead to June
- First harvests: sweet corn
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.
Caldwell County, Texas is in USDA Zone 9a. The average last spring frost is February 27 and the first fall frost is December 1, giving you a growing season of approximately 277 days.
At an elevation of 3,482 feet, Caldwell County receives approximately 60.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, 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.
Caldwell County Soil Profile
Soil Type
Clay
Soil pH
6.8-8.1
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.
Soil Compatibility in Caldwell County
How your county's soil matches Sweet Corn's growing requirements.
Soil pH
Your soil pH (6.8–8.1) is more alkaline than Sweet Corn prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Heavy clay soil (43% clay) in Caldwell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (3.3%). Annual compost additions will help Sweet Corn.
How to Plant Sweet Corn
Succession Planting Sweet Corn
Sow every 6.9 weeks. Last sowing by Sep 02 to harvest before frost.
Plant Water Budget
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Mar | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Apr | 6.5" | 6" | 0.5" | 💧 Light watering |
| May | 6.5" | 9.9" | 0" | ✅ Rainfall sufficient |
| Jun | 6.5" | 9.2" | 0" | ✅ Rainfall sufficient |
| Jul | 6.5" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 6.5" | 7.9" | 0" | ✅ Rainfall sufficient |
| Sep | 6.5" | 5.6" | 0.9" | 💧 Light watering |
| Oct | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Nov | 6.5" | 1.8" | 4.7" | 🚿 Regular watering |
| Dec | 6.5" | 1.5" | 5" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Caldwell 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 Planting Timeline — Caldwell County, TX
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 6 | Mar 6 – Mar 27 |
| Harvest | May 8 | May 8 – Jun 19 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | — |
| 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
277 days in Caldwell County
Growing Tips for Sweet Corn in Caldwell County
Direct sow Sweet Corn outdoors after February 27 in Caldwell County when soil has warmed and frost danger has passed.
With Caldwell County's clay soil (43% clay), work in 3-4 inches of compost before planting Sweet Corn. Avoid tilling when soil is wet to prevent compaction.
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
Check more plant combinations with our Companion Planting Checker →
Sweet Corn in Other Locations
Frequently Asked Questions
When should I plant Sweet Corn in Caldwell County, TX?
Caldwell County is in Zone 9a with an average last frost of February 27. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Caldwell County, TX?
Caldwell County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 27 and first fall frost is December 1.
Your Caldwell County Garden Planner — Free
A 24-page printable planner built for Caldwell 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.