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When to Plant Watermelon in Smith County, MS

Smith County, Mississippi Zone 8b May

Your May planting checklist for Smith County, Mississippi

Each item below is timed to Smith County, Mississippi's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 13
Avg. first frost November 13
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
A few tasks this May that'll pay off in June
  • 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.

Smith County, Mississippi is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 13, giving you a growing season of approximately 245 days.

At an elevation of 492 feet, Smith County receives approximately 58.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 96°F, so Watermelon may need afternoon shade and extra watering during peak heat. 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.

Smith County, MS (Zone 8b) Long season
245 days
Last Spring Frost March 13
245 growing days
First Fall Frost November 13

Smith County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Feb 6 Transplant: Mar 20 🍅 Harvest: May 29 – Jul 17
Recommended (50%) ✓ Fits season (112 days to spare)
Start indoors: Feb 13 Transplant: Mar 27 🍅 Harvest: Jun 5 – Jul 24
Safe Start (90%) ✓ Fits season (103 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 Smith County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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 245-day season

Sow every 8 weeks. Last sowing by Aug 05 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,088 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 5.2" 0" ❄️ Dormant
Feb 5.1" 0" ❄️ Dormant
Mar 6.5" 5.6" 0.9" 💧 Light watering
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 4.6" 1.9" 💧 Light watering
Jun 6.5" 5.2" 1.3" 💧 Light watering
Jul 6.5" 6" 0.5" 💧 Light watering
Aug 6.5" 5.1" 1.4" 💧 Light watering
Sep 6.5" 4.8" 1.7" 💧 Light watering
Oct 6.5" 4.1" 2.4" 💧 Light watering
Nov 6.5" 4.2" 2.3" 💧 Light watering
Dec 4.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Smith 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 ~1,870 GDD — county provides 5,390 GDD Excellent fit

Watermelon Planting Timeline — Smith County, MS

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 20 Mar 20 – Apr 10
Harvest June 5 Jun 5 – Jul 24

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: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

245 days in Smith County

Growing Tips for Watermelon in Smith County

Direct sow Watermelon outdoors after March 13 in Smith County when soil has warmed and frost danger has passed.

With Smith County's clay soil (33% clay), work in 3-4 inches of compost before planting Watermelon. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 96°F in Smith 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 Smith 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 Smith County, MS?

Smith County is in Zone 8b with an average last frost of March 13. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Smith County, MS?

Smith County, Mississippi is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 13.

🌱

Your Smith County Garden Planner — Free

A 24-page printable planner built for Smith 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 Smith County, MS. 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.