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When to Plant Watermelon in Wabasha County, MN

Wabasha County, Minnesota Zone 4b May

Your May game plan for Wabasha County, Minnesota

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

Avg. last frost April 28
Avg. first frost October 8
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Plant out watermelon

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Seed watermelon outdoors

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

To set up a strong June, finish these tasks
  • 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.

Wabasha County, Minnesota is in USDA Zone 4b. The average last spring frost is April 28 and the first fall frost is October 8, giving you a growing season of approximately 163 days.

At an elevation of 1,270 feet, Wabasha County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Watermelon to ensure they mature before fall.

Wabasha County, MN (Zone 4b) Moderate season
163 days
Last Spring Frost April 28
163 growing days
First Fall Frost October 8

Wabasha County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Mar 10 Transplant: May 12 🍅 Harvest: Jul 21 – Sep 8
Recommended (50%) ✓ Fits season (23 days to spare)
Start indoors: Mar 17 Transplant: May 19 🍅 Harvest: Jul 28 – Sep 15
Safe Start (90%) ✓ Fits season (22 days to spare)
Start indoors: Apr 3 Transplant: Jun 5 🍅 Harvest: Aug 14 – Oct 2

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 Wabasha County

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

Soil pH

Your soil pH (6.2–6.7) is within Watermelon's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Watermelon will thrive.

How to Plant Watermelon

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

Succession Planting Watermelon

2
successive plantings in your 163-day season

Sow every 8 weeks. Last sowing by Jun 30 to harvest before frost.

Plant 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 890 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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 6.5" 3.1" 3.4" 🚿 Regular watering
May 6.5" 4.3" 2.2" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 3.2" 3.3" 🚿 Regular watering
Sep 6.5" 3" 3.5" 🚿 Regular watering
Oct 6.5" 2.8" 3.7" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Wabasha 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 ~914 GDD — county provides 1,752 GDD Excellent fit

Watermelon Planting Timeline — Wabasha County, MN

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 12 May 12 – Jun 2
Harvest July 28 Jul 28 – Sep 15

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
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 4b

📆 Growing Season

163 days in Wabasha County

Growing Tips for Watermelon in Wabasha County

Direct sow Watermelon outdoors after April 28 in Wabasha 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.

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 Wabasha County, MN?

Wabasha County is in Zone 4b with an average last frost of April 28. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wabasha County, MN?

Wabasha County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 28 and first fall frost is October 8.

🌱

Your Wabasha County Garden Planner — Free

A 24-page printable planner built for Wabasha County (Zone 4b). 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 Wabasha County, MN. 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.