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When to Plant Squash (Winter) in Teton County, MT

Teton County, Montana Zone 4b May

Your May gardening checklist

Each item below is timed to Teton County, Montana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 25
Avg. first frost September 16
Soil temp (4") 28°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
A few tasks this May that'll pay off in June
  • Transplants going out: squash (winter)
  • Direct-sowing: squash (winter)

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Winter squash includes butternut, acorn, delicata, and hubbard varieties grown to full maturity with hard rinds for storage. They develop sweet, dense flesh.

Teton County, Montana is in USDA Zone 4b. The average last spring frost is May 25 and the first fall frost is September 16, giving you a growing season of approximately 114 days.

At an elevation of 8,276 feet, Teton County receives approximately 15.1 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Squash (Winter) to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Squash (Winter) successfully. Mulch heavily to conserve soil moisture.

Teton County, MT (Zone 4b) Short season
114 days
Last Spring Frost May 25
114 growing days
First Fall Frost September 16
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Teton County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 10 🍅 Harvest: Sep 2 – Oct 28
Recommended (50%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jun 15 🍅 Harvest: Sep 7 – Nov 2
Safe Start (90%) ✗ May not fit
Start indoors: Apr 30 Transplant: Jul 2 🍅 Harvest: Sep 24 – Nov 19

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 Teton County

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

Soil pH

Your soil pH (6.6–7.6) is more alkaline than Squash (Winter) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Squash (Winter).

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Squash (Winter).

How to Plant Squash (Winter)

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 905 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Squash (Winter)

Squash (Winter) 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 (Winter) Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 1.7" 2.6" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Squash (Winter) 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 (Winter) needs ~1,300 GDD — county provides 1,482 GDD Good fit

Squash (Winter) Planting Timeline — Teton County, MT

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 – Apr 27
Transplant Outdoors June 15 Jun 15 – Jun 29
Direct Sow June 8 Jun 8 – Jun 29
Harvest September 7 Sep 7 – Nov 2

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

114 days in Teton County

Growing Tips for Squash (Winter) in Teton County

Direct sow Squash (Winter) outdoors after May 25 in Teton County when soil has warmed and frost danger has passed.

Your 114.0-day growing season in Teton County is tight for Squash (Winter) (80.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Teton County receives only 15" of rain annually. Squash (Winter) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost on rich mounds. Allow ample space for sprawling vines. Cure harvested fruits in the sun for 10 days before storing in a cool, dry place.

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 (Winter) in Teton County, MT?

Teton County is in Zone 4b with an average last frost of May 25. Plan your Squash (Winter) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Teton County, MT?

Teton County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 25 and first fall frost is September 16.

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Your Teton County Garden Planner — Free

A 24-page printable planner built for Teton 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 Teton County, MT. 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.