When to Plant Watermelon in Bexar County, TX
Your May planting checklist for Bexar County, Texas
Here's what deserves your attention in Bexar 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 watermelon
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Coming up in June — start thinking about
- First harvests: watermelon
Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.
Bexar County, Texas is in USDA Zone 9a. The average last spring frost is March 11 and the first fall frost is November 17, giving you a growing season of approximately 251 days.
At an elevation of 3,197 feet, Bexar County receives approximately 52.1 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Watermelon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watermelon root diseases.
Bexar County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.8
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 Bexar County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (6.5–7.8) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Bexar County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Watermelon.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Aug 09 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Watermelon
Watermelon 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 | Watermelon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Apr | 6.5" | 5.6" | 0.9" | 💧 Light watering |
| May | 6.5" | 7.5" | 0" | ✅ Rainfall sufficient |
| Jun | 6.5" | 8.2" | 0" | ✅ Rainfall sufficient |
| Jul | 6.5" | 6.3" | 0.2" | 💧 Light watering |
| Aug | 6.5" | 6.3" | 0.2" | 💧 Light watering |
| Sep | 6.5" | 4.9" | 1.6" | 💧 Light watering |
| Oct | 6.5" | 3.5" | 3" | 💧 Light watering |
| Nov | 6.5" | 1.9" | 4.6" | 🚿 Regular watering |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Bexar County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watermelon 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.
Watermelon Planting Timeline — Bexar County, TX
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 11 | Feb 11 – Feb 25 |
| Transplant Outdoors | March 18 | Mar 18 – Apr 1 |
| Direct Sow | March 11 | Mar 11 – Apr 1 |
| Harvest | May 27 | May 27 – Jul 15 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
251 days in Bexar County
Growing Tips for Watermelon in Bexar County
Direct sow Watermelon outdoors after March 11 in Bexar County when soil has warmed and frost danger has passed.
Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.
Recommended Watermelon Varieties for Bexar County
Full-size melons that thrive with your long season
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Bexar County, TX?
Bexar County is in Zone 9a with an average last frost of March 11. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bexar County, TX?
Bexar County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 11 and first fall frost is November 17.
Your Bexar County Garden Planner — Free
A 24-page printable planner built for Bexar 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.