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When to Plant Watermelon in Jackson County, TX

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.

Jackson County, Texas is in USDA Zone 9a. The average last spring frost is February 21 and the first fall frost is December 5, giving you a growing season of approximately 287 days.

At an elevation of 286 feet, Jackson County receives approximately 64.3 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, so Watermelon may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watermelon root diseases.

Jackson County, TX (Zone 9a) Year-round
287 days
Last Spring Frost February 21
287 growing days
First Fall Frost December 5

Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (163 days to spare)
Start indoors: Jan 11 Transplant: Feb 15 🍅 Harvest: Apr 26 – Jun 14
Recommended (50%) ✓ Fits season (161 days to spare)
Start indoors: Jan 24 Transplant: Feb 28 🍅 Harvest: May 9 – Jun 27
Safe Start (90%) ✓ Fits season (153 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: May 30 – Jul 18

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 Jackson County

How your county's soil matches Watermelon's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.2) is within Watermelon's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Jackson County is excellent for Watermelon โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Watermelon.

Organic Matter

Organic matter is moderate (2.0%). Annual compost additions will help Watermelon.

How to Plant Watermelon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Watermelon

4
successive plantings in your 287-day season

Sow every 8 weeks. Last sowing by Aug 27 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,595 gal / 100 sq ft

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 โ€” 1.7" 0" โ„๏ธ Dormant
Feb 6.5" 2.1" 4.4" ๐Ÿšฟ Regular watering
Mar 6.5" 3.9" 2.6" ๐Ÿ’ง Light watering
Apr 6.5" 6.5" 0" โœ… Rainfall sufficient
May 6.5" 9" 0" โœ… Rainfall sufficient
Jun 6.5" 10.4" 0" โœ… Rainfall sufficient
Jul 6.5" 7.9" 0" โœ… Rainfall sufficient
Aug 6.5" 8" 0" โœ… Rainfall sufficient
Sep 6.5" 6" 0.5" ๐Ÿ’ง Light watering
Oct 6.5" 4.8" 1.7" ๐Ÿ’ง Light watering
Nov 6.5" 2.3" 4.2" ๐Ÿšฟ Regular watering
Dec 6.5" 1.7" 4.8" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Jackson County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~2,316 GDD — county provides 7,848 GDD Excellent fit

Watermelon Planting Timeline โ€” Jackson County, TX

Watermelon Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 โ€“ Feb 7
Transplant Outdoors February 28 Feb 28 โ€“ Mar 14
Direct Sow February 21 Feb 21 โ€“ Mar 14
Harvest May 9 May 9 โ€“ Jun 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

287 days in Jackson County

Growing Tips for Watermelon in Jackson County

Direct sow Watermelon outdoors after February 21 in Jackson County when soil has warmed and frost danger has passed.

With summer highs reaching 103ยฐF in Jackson County, provide afternoon shade for Watermelon and water deeply in the morning.

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 Jackson County

Full-size melons that thrive with your long season

Crimson Sweet (85d) Charleston Gray (85d) Moon and Stars (95d)

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 Jackson County, TX?

Jackson County is in Zone 9a with an average last frost of February 21. Plan your Watermelon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jackson County, TX?

Jackson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 21 and first fall frost is December 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jackson County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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