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When to Plant Patty Pan Squash in Flathead County, MT

Flathead County, Montana Zone 5a May

This month in Flathead County, Montana

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.

Avg. last frost June 3
Avg. first frost September 10
Soil temp (4") 41°F
Watering High
Pest pressure Low
Daylight 15 hrs
Coming up in June — start thinking about
  • Transplants going out: patty pan squash
  • Direct-sowing: patty pan squash

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Patty pan squash is a summer squash with a distinctive flying-saucer shape and scalloped edges. It comes in white, yellow, and green varieties with a mild, nutty flavor.

Flathead County, Montana is in USDA Zone 5a. The average last spring frost is June 3 and the first fall frost is September 10, giving you a growing season of approximately 99 days.

At an elevation of 6,233 feet, Flathead County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Patty Pan Squash during the growing season.

Flathead County, MT (Zone 5a) Very short season
99 days
Last Spring Frost June 3
99 growing days
First Fall Frost September 10
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Flathead County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Apr 17 Transplant: Jun 5 🍅 Harvest: Jul 24 – Aug 21
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Apr 29 Transplant: Jun 17 🍅 Harvest: Aug 5 – Sep 2
Safe Start (90%) ✓ Fits season (1 days to spare)
Start indoors: May 18 Transplant: Jul 6 🍅 Harvest: Aug 24 – Sep 21

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 Flathead County

How your county's soil matches Patty Pan Squash's growing requirements.

Soil pH

Your soil pH (6.6–8.4) overlaps with Patty Pan Squash's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Patty Pan Squash.

How to Plant Patty Pan Squash

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

Succession Planting Patty Pan Squash

2
successive plantings in your 99-day season

Sow every 5.1 weeks. Last sowing by Jul 12 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 129 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Patty Pan Squash

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

Month Patty Pan Squash Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 2.7" 0" ❄️ Dormant
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Patty Pan 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.

Patty Pan Squash needs ~801 GDD — county provides 1,509 GDD Excellent fit

Patty Pan Squash Planting Timeline — Flathead County, MT

Patty Pan Squash Planting Calendar

Activity When Date Range
Start Indoors April 29 Apr 29 – May 13
Transplant Outdoors June 17 Jun 17 – Jul 1
Direct Sow June 10 Jun 10 – Jul 1
Harvest August 5 Aug 5 – Sep 2

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

99 days in Flathead County

Growing Tips for Patty Pan Squash in Flathead County

Direct sow Patty Pan Squash outdoors after June 03 in Flathead County when soil has warmed and frost danger has passed.

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

Flathead County receives only 21" of rain annually. Patty Pan Squash needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Harvest when 2-4 inches across for best texture and flavor. Larger fruits become seedy and tough. Very prolific producers in warm weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Patty Pan Squash in Flathead County, MT?

Flathead County is in Zone 5a with an average last frost of June 3. Plan your Patty Pan Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Flathead County, MT?

Flathead County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 3 and first fall frost is September 10.

🌱

Your Flathead County Garden Planner — Free

A 24-page printable planner built for Flathead County (Zone 5a). 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 Flathead 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.