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When to Plant Watermelon in Collin 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.

Collin County, Texas is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94°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.

Collin County, TX (Zone 8b) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20

Collin County Soil Profile

Soil Type

Clay

Soil pH

6.0-7.0

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 Collin County's 255-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Watermelon Planting Timeline — Collin County, TX

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors March 24 Mar 24 – Apr 7
Direct Sow March 17 Mar 17 – Apr 7
Harvest June 2 Jun 2 – Jul 21

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May
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 8b

📆 Growing Season

255 days in Collin County

Growing Tips for Collin 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 Collin County, TX?

Collin County is in Zone 8b with an average last frost of March 10. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Collin County, TX?

Collin County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 20.

🌱

Your Collin County Garden Planner — Free

A 22-page printable planner built for Collin County (Zone 8b). 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 Collin County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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