When to Plant Sweet Corn in Harris County, TX
Your May gardening checklist
Your Harris County, Texas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Harvest sweet corn as they ripen
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Before June arrives, get these ready
- 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.
Harris County, Texas is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.
At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Sweet Corn may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Corn will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Corn root diseases.
Harris County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.3-6.5
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 Harris County
How your county's soil matches Sweet Corn's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Sweet Corn prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Harris County warms quickly in spring but drains fast. Sweet Corn will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is moderate (2.2%). 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 05 to harvest before frost.
Plant Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| Mar | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Apr | 6.5" | 7.4" | 0" | ✅ Rainfall sufficient |
| May | 6.5" | 10.1" | 0" | ✅ Rainfall sufficient |
| Jun | 6.5" | 10" | 0" | ✅ Rainfall sufficient |
| Jul | 6.5" | 9.6" | 0" | ✅ Rainfall sufficient |
| Aug | 6.5" | 8.5" | 0" | ✅ Rainfall sufficient |
| Sep | 6.5" | 6.3" | 0.2" | 💧 Light watering |
| Oct | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Nov | 6.5" | 2.2" | 4.3" | 🚿 Regular watering |
| Dec | 6.5" | 1.6" | 4.9" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Harris 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 — Harris County, TX
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | February 21 | Feb 21 – Mar 14 |
| Harvest | April 25 | Apr 25 – Jun 6 |
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
1.5"/week · 1-2 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9b
📆 Growing Season
293 days in Harris County
Growing Tips for Sweet Corn in Harris County
Direct sow Sweet Corn outdoors after February 14 in Harris County when soil has warmed and frost danger has passed.
Sandy soil in Harris County dries quickly — mulch Sweet Corn with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 102°F in Harris County, provide afternoon shade for Sweet Corn and water deeply in the morning.
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 Harris County, TX?
Harris County is in Zone 9b with an average last frost of February 14. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harris County, TX?
Harris County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 4.
Your Harris County Garden Planner — Free
A 24-page printable planner built for Harris County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.