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When to Plant Watermelon in Armstrong 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.

Armstrong County, Texas is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.

At an elevation of 2,506 feet, Armstrong County receives approximately 57.6 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Watermelon may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Watermelon will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watermelon root diseases.

Armstrong County, TX (Zone 7a) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24

Armstrong County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

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 Armstrong County's 192-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 3.6" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4.3" 2.2" 2.1" 💧 Light watering
May 4.3" 1.4" 2.9" 🚿 Regular watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 8.8" 0" ✅ Rainfall sufficient
Aug 4.3" 13.9" 0" ✅ Rainfall sufficient
Sep 4.3" 6.9" 0" ✅ Rainfall sufficient
Oct 4.3" 5" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

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

Watermelon Planting Timeline — Armstrong County, TX

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest July 8 Jul 8 – Aug 26

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
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 7a

📆 Growing Season

192 days in Armstrong County

Growing Tips for Armstrong 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 Armstrong County, TX?

Armstrong County is in Zone 7a with an average last frost of April 15. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Armstrong County, TX?

Armstrong County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 24.

🌱

Your Armstrong County Garden Planner — Free

A 22-page printable planner built for Armstrong County (Zone 7a). 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 Armstrong County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

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