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When to Plant Watermelon in LaSalle Parish, LA

LaSalle Parish, Louisiana Zone 8b May

May in LaSalle Parish, Louisiana — your action list

Each item below is timed to LaSalle Parish, Louisiana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 2
Avg. first frost November 19
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Pick watermelon

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

June will be here before you know it — start on
  • First harvests: watermelon

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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.

LaSalle Parish, Louisiana is in USDA Zone 8b. The average last spring frost is March 2 and the first fall frost is November 19, giving you a growing season of approximately 262 days.

At an elevation of 262 feet, LaSalle Parish receives approximately 52.2 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.

LaSalle Parish, LA (Zone 8b) Long season
262 days
Last Spring Frost March 2
262 growing days
First Fall Frost November 19

LaSalle Parish Soil Profile

Soil Type

Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (133 days to spare)
Start indoors: Jan 23 Transplant: Mar 6 🍅 Harvest: May 15 – Jul 3
Recommended (50%) ✓ Fits season (129 days to spare)
Start indoors: Feb 2 Transplant: Mar 16 🍅 Harvest: May 25 – Jul 13
Safe Start (90%) ✓ Fits season (135 days to spare)
Start indoors: Feb 21 Transplant: Apr 4 🍅 Harvest: Jun 13 – Aug 1

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 LaSalle Parish

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

Soil pH

Your soil pH (6.2–7.2) is within Watermelon's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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 262-day season

Sow every 8 weeks. Last sowing by Aug 11 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,546 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 4.6" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 6.5" 4.8" 1.7" 💧 Light watering
Apr 6.5" 4.4" 2.1" 💧 Light watering
May 6.5" 3.9" 2.6" 💧 Light watering
Jun 6.5" 4" 2.5" 💧 Light watering
Jul 6.5" 5.8" 0.7" 💧 Light watering
Aug 6.5" 5.3" 1.2" 💧 Light watering
Sep 6.5" 4.1" 2.4" 💧 Light watering
Oct 6.5" 3.5" 3" 💧 Light watering
Nov 6.5" 3.6" 2.9" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in LaSalle Parish). 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 5,567 GDD Excellent fit

Watermelon Planting Timeline — LaSalle Parish, LA

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 16 Mar 16 – Mar 30
Direct Sow March 9 Mar 9 – Mar 30
Harvest May 25 May 25 – Jul 13

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
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

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

262 days in LaSalle Parish

Growing Tips for Watermelon in LaSalle Parish

Direct sow Watermelon outdoors after March 02 in LaSalle Parish 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 LaSalle Parish

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 LaSalle Parish, LA?

LaSalle Parish is in Zone 8b with an average last frost of March 2. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is LaSalle Parish, LA?

LaSalle Parish, Louisiana is in USDA Hardiness Zone 8b. The average last spring frost is March 2 and first fall frost is November 19.

🌱

Your LaSalle Parish Garden Planner — Free

A 24-page printable planner built for LaSalle Parish (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 LaSalle Parish, LA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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