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When to Plant Watermelon in Caldwell County, TX

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.

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 Watermelon during the growing season. Clay soil retains moisture well for Watermelon, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watermelon root diseases.

Caldwell County, TX (Zone 9a) Year-round
277 days
Last Spring Frost February 27
277 growing days
First Fall Frost December 1

Caldwell County Soil Profile

Soil Type

Clay

Soil pH

6.8-8.1

Drainage

Well Drained

How Much Watermelon to Grow

15-20 lbs
Average yield per plant
1
Plants per person
2 sq ft
Space per person

For a family of 4, plant approximately 4 watermelon plants in about 8 sq ft. In Caldwell County's 277-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Watermelon

Watermelon needs approximately 1 inches of water per week (4.3" 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 4.3" 2.1" 2.2" 🚿 Regular watering
Mar 4.3" 4.1" 0.2" 💧 Light watering
Apr 4.3" 6" 0" ✅ Rainfall sufficient
May 4.3" 9.9" 0" ✅ Rainfall sufficient
Jun 4.3" 9.2" 0" ✅ Rainfall sufficient
Jul 4.3" 7.5" 0" ✅ Rainfall sufficient
Aug 4.3" 7.9" 0" ✅ Rainfall sufficient
Sep 4.3" 5.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 4.3" 1.8" 2.5" 🚿 Regular watering
Dec 4.3" 1.5" 2.8" 🚿 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.

Watermelon Planting Timeline — Caldwell County, TX

Watermelon Planting Calendar

Activity When Date Range
Start Indoors January 30 Jan 30 – Feb 13
Transplant Outdoors March 6 Mar 6 – Mar 20
Direct Sow February 27 Feb 27 – Mar 20
Harvest May 15 May 15 – Jul 3

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Caldwell County

Growing Tips for Caldwell County

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.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watermelon in Caldwell County, TX?

Caldwell County is in Zone 9a with an average last frost of February 27. Plan your Watermelon 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 22-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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Caldwell County, TX. Local conditions may vary. Last updated: August 2026.

Sources & credits

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