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When to Plant Pumpkin in Park County, MT

Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.

Park County, Montana is in USDA Zone 4b. The average last spring frost is May 24 and the first fall frost is September 20, giving you a growing season of approximately 119 days.

At an elevation of 6,994 feet, Park County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Park County, MT (Zone 4b) Short season
119 days
Last Spring Frost May 24
119 growing days
First Fall Frost September 20

Park County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 2 Transplant: Jun 4 🍅 Harvest: Sep 3 – Oct 22
Recommended (50%) ✗ May not fit
Start indoors: Apr 12 Transplant: Jun 14 🍅 Harvest: Sep 13 – Nov 1
Safe Start (90%) ✗ May not fit
Start indoors: May 6 Transplant: Jul 8 🍅 Harvest: Oct 7 – Nov 25

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 275 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Pumpkin needs ~1,025 GDD — county provides 1,190 GDD Good fit

Pumpkin Planting Timeline โ€” Park County, MT

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors April 12 Apr 12 โ€“ Apr 26
Transplant Outdoors June 14 Jun 14 โ€“ Jun 28
Direct Sow June 7 Jun 7 โ€“ Jun 28
Harvest September 13 Sep 13 โ€“ Nov 1

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

85โ€“120 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 4b

Growing Season

119 days

Growing Tips for Park County

Direct sow on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Pumpkin in Park County, MT?

Park County is in Zone 4b with an average last frost of May 24. Plan your Pumpkin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Park County, MT?

Park County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 24 and first fall frost is September 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Park County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Park County, MT. Local conditions may vary. Last updated: April 2026.