Blog

When to Plant Butternut Squash in Edmunds County, SD

Edmunds County, South Dakota Zone 4b May

May in Edmunds County, South Dakota — your action list

May is a pivotal month for Edmunds County, South Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 10
Avg. first frost September 28
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Harden off and plant butternut squash

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Scatter butternut squash into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Get ahead of June
  • Starting indoors: butternut squash

Instant PDF download. No spam, unsubscribe any time.

Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.

Edmunds County, South Dakota is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is September 28, giving you a growing season of approximately 141 days.

At an elevation of 935 feet, Edmunds County receives approximately 33.7 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Butternut Squash to ensure they mature before fall.

Edmunds County, SD (Zone 4b) Short season
141 days
Last Spring Frost May 10
141 growing days
First Fall Frost September 28
Share this guide:

Edmunds County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 20 Transplant: May 22 🍅 Harvest: Aug 21 – Sep 25
Recommended (50%) ✗ May not fit
Start indoors: Mar 29 Transplant: May 31 🍅 Harvest: Aug 30 – Oct 4
Safe Start (90%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 9 🍅 Harvest: Sep 8 – Oct 13

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 Edmunds County

How your county's soil matches Butternut Squash's growing requirements.

Soil pH

Your soil pH (6.4–7.6) overlaps with Butternut Squash's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Edmunds County is excellent for Butternut Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Butternut Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 145 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Butternut Squash

Butternut Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Butternut Squash Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.8" 4.5" 0.3" 💧 Light watering
Jun 4.8" 6.1" 0" ✅ Rainfall sufficient
Jul 4.8" 4.5" 0.3" 💧 Light watering
Aug 4.8" 4.4" 0.4" 💧 Light watering
Sep 4.8" 2.9" 1.9" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Butternut Squash 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.

Butternut Squash needs ~1,121 GDD — county provides 1,621 GDD Excellent fit

Butternut Squash Planting Timeline — Edmunds County, SD

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest August 30 Aug 30 – Oct 4

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 Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October Harvest
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

141 days in Edmunds County

Growing Tips for Butternut Squash in Edmunds County

Direct sow Butternut Squash outdoors after May 10 in Edmunds County when soil has warmed and frost danger has passed.

Common pests for Butternut Squash 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 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Edmunds County, SD?

Edmunds County is in Zone 4b with an average last frost of May 10. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Edmunds County, SD?

Edmunds County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is September 28.

🌱

Your Edmunds County Garden Planner — Free

A 24-page printable planner built for Edmunds 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Edmunds County, SD. 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.