When to Plant Watermelon in Winona County, MN
What to do in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Move watermelon from tray to bed
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Outdoor sowing time: watermelon
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Before June arrives, get these ready
- Starting indoors: watermelon
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.
Winona County, Minnesota is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.
At an elevation of 1,396 feet, Winona County receives approximately 37.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Watermelon to ensure they mature before fall.
Winona County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Winona County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (6.3–6.8) is within Watermelon's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Winona County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.2%) — Watermelon will thrive.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Jun 29 to harvest before frost.
Plant Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| May | 6.5" | 4.5" | 2" | 💧 Light watering |
| Jun | 6.5" | 4.2" | 2.3" | 💧 Light watering |
| Jul | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Aug | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Sep | 6.5" | 2.8" | 3.7" | 🚿 Regular watering |
| Oct | 6.5" | 3.2" | 3.3" | 🚿 Regular watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Winona 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 Planting Timeline — Winona County, MN
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 19 | Mar 19 – Apr 2 |
| Transplant Outdoors | May 21 | May 21 – Jun 4 |
| Direct Sow | May 14 | May 14 – Jun 4 |
| Harvest | July 30 | Jul 30 – Sep 17 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| 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
160 days in Winona County
Growing Tips for Watermelon in Winona County
Direct sow Watermelon outdoors after April 30 in Winona 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 Winona County
Compact, early melons for shorter seasons
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Winona County, MN?
Winona County is in Zone 4b 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 Winona County, MN?
Winona County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.
Your Winona County Garden Planner — Free
A 24-page printable planner built for Winona 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.