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When to Plant Watermelon in Kendall County, TX

Watermelon
Kendall County, Texas Zone 8b August

Kendall County, Texas gardeners: here's your August plan

Your garden in Kendall County, Texas is working on a schedule, even when you're not. Here's where you should be this August.

Avg. last frost March 9
Avg. first frost November 20
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 13.1 hrs

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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.

Kendall County, Texas is in USDA Zone 8b. The average last spring frost is March 9 and the first fall frost is November 20, giving you a growing season of approximately 256 days.

At an elevation of 2,187 feet, Kendall County receives approximately 54.6 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, 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.

Kendall County, TX (Zone 8b) Long season
256 days
Last Spring Frost March 9
256 growing days
First Fall Frost November 20

Kendall County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.4

Drainage

Well Drained

Watermelon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Jan 31 Transplant: Mar 14 🍅 Harvest: May 23 – Jul 11
Recommended (50%) ✓ Fits season (123 days to spare)
Start indoors: Feb 9 Transplant: Mar 23 🍅 Harvest: Jun 1 – Jul 20
Safe Start (90%) ✓ Fits season (115 days to spare)
Start indoors: Mar 10 Transplant: Apr 21 🍅 Harvest: Jun 30 – Aug 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 Kendall County

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

Soil pH

Your soil pH (6.4–7.4) is within Watermelon's preferred range (6.0–7.5).

Soil Texture

The loam soil in Kendall County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). 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 256-day season

Sow every 8 weeks. Last sowing by Aug 12 to harvest before frost.

Watermelon Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,377 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 1.5" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 6.5" 3.3" 3.2" 💧 Light watering
Apr 6.5" 6.5" 0" ✅ Rainfall sufficient
May 6.5" 7.6" 0" ✅ Rainfall sufficient
Jun 6.5" 8.2" 0" ✅ Rainfall sufficient
Jul 6.5" 6.9" 0" ✅ Rainfall sufficient
Aug 6.5" 6.3" 0.2" 💧 Light watering
Sep 6.5" 5.4" 1.1" 💧 Light watering
Oct 6.5" 3.4" 3.1" 💧 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 Kendall 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 needs ~1,806 GDD — county provides 5,440 GDD Excellent fit

Watermelon Planting Timeline — Kendall County, TX

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 – Feb 23
Transplant Outdoors March 23 Mar 23 – Apr 6
Direct Sow March 16 Mar 16 – Apr 6
Harvest June 1 Jun 1 – Jul 20

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

1.5"/week · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

256 days in Kendall County

Growing Tips for Watermelon in Kendall County

Direct sow Watermelon outdoors after March 09 in Kendall 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 Kendall 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 Kendall County, TX?

Kendall County is in Zone 8b with an average last frost of March 9. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kendall County, TX?

Kendall County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 9 and first fall frost is November 20.

🌱

Your Kendall County Garden Planner — Free

A 22-page printable planner built for Kendall 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.

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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 Kendall 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.