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When to Plant Watermelon in Logan County, KS

Logan County, Kansas Zone 6a May

Your May game plan for Logan County, Kansas

Your garden in Logan County, Kansas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 30
Avg. first frost October 12
Soil temp (4") 60°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Harden off and plant watermelon

    Frost risk is low now in Logan County, Kansas. If you've been covering beds overnight, you can stop.

  2. Plant watermelon from seed, right in the garden

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

Before June arrives, get these ready
  • Starting indoors: 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.

Logan County, Kansas is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 12, giving you a growing season of approximately 165 days.

At an elevation of 764 feet, Logan County receives approximately 22.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Watermelon during the growing season.

Logan County, KS (Zone 6a) Moderate season
165 days
Last Spring Frost April 30
165 growing days
First Fall Frost October 12
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Logan County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Mar 21 Transplant: May 9 🍅 Harvest: Jul 18 – Sep 5
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Mar 26 Transplant: May 14 🍅 Harvest: Jul 23 – Sep 10
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Apr 8 Transplant: May 27 🍅 Harvest: Aug 5 – Sep 23

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 Logan County

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

Soil pH

Your soil pH (6.3–7.4) is within Watermelon's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Watermelon.

How to Plant Watermelon

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

Succession Planting Watermelon

2
successive plantings in your 165-day season

Sow every 8 weeks. Last sowing by Jul 04 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,634 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.3" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 6.5" 2.4" 4.1" 🚿 Regular watering
May 6.5" 2.9" 3.6" 🚿 Regular watering
Jun 6.5" 1.4" 5.1" 🚿 Regular watering
Jul 6.5" 2" 4.5" 🚿 Regular watering
Aug 6.5" 2.2" 4.3" 🚿 Regular watering
Sep 6.5" 2.1" 4.4" 🚿 Regular watering
Oct 6.5" 1.8" 4.7" 🚿 Regular watering
Nov 1.8" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Logan 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 ~1,169 GDD — county provides 2,268 GDD Excellent fit

Watermelon Planting Timeline — Logan County, KS

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 7 May 7 – May 28
Harvest July 23 Jul 23 – Sep 10

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

165 days in Logan County

Growing Tips for Watermelon in Logan County

Direct sow Watermelon outdoors after April 30 in Logan 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.

Logan County receives only 22" of rain annually. Watermelon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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.

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 Logan County, KS?

Logan County is in Zone 6a with an average last frost of April 30. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Logan County, KS?

Logan County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 12.

🌱

Your Logan County Garden Planner — Free

A 24-page printable planner built for Logan County (Zone 6a). 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 Logan County, KS. 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.