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When to Plant Squash (Summer) in Buffalo County, WI

Buffalo County, Wisconsin Zone 4b May

May to-do list for Buffalo County, Wisconsin

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Buffalo County, Wisconsin.

Avg. last frost May 12
Avg. first frost September 30
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Sow squash (summer) where they'll grow

    Your soil is 56°F — warm enough for these to germinate without babying.

Coming up in June — start thinking about
  • Transplants going out: squash (summer)
  • Starting indoors: squash (summer)

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Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Buffalo County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is September 30, giving you a growing season of approximately 141 days.

At an elevation of 661 feet, Buffalo County receives approximately 36.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Squash (Summer) to ensure they mature before fall.

Buffalo County, WI (Zone 4b) Short season
141 days
Last Spring Frost May 12
141 growing days
First Fall Frost September 30

Buffalo County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 21 Transplant: May 23 🍅 Harvest: Jul 11 – Sep 12
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Mar 31 Transplant: Jun 2 🍅 Harvest: Jul 21 – Sep 22
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Apr 8 Transplant: Jun 10 🍅 Harvest: Jul 29 – Sep 30

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 Buffalo County

How your county's soil matches Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (6.0–6.9) is within Squash (Summer)'s preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Buffalo County is excellent for Squash (Summer) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) — Squash (Summer) will thrive.

How to Plant Squash (Summer)

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

Succession Planting Squash (Summer)

3
successive plantings in your 141-day season

Sow every 5.1 weeks. Last sowing by Jul 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Squash (Summer)

Squash (Summer) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Squash (Summer) Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 2.8" 0" ❄️ Dormant
Nov 2.2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Buffalo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Squash (Summer) 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.

Squash (Summer) needs ~550 GDD — county provides 1,410 GDD Excellent fit

Squash (Summer) Planting Timeline — Buffalo County, WI

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest July 21 Jul 21 – Sep 22

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May 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"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

141 days in Buffalo County

Growing Tips for Squash (Summer) in Buffalo County

Direct sow Squash (Summer) outdoors after May 12 in Buffalo County when soil has warmed and frost danger has passed.

Common pests for Squash (Summer) in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Buffalo County, WI?

Buffalo County is in Zone 4b with an average last frost of May 12. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Buffalo County, WI?

Buffalo County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is September 30.

🌱

Your Buffalo County Garden Planner — Free

A 24-page printable planner built for Buffalo 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 Buffalo County, WI. 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.