When to Plant Pumpkin in Custer 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.
Custer County, Montana is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 27, giving you a growing season of approximately 136 days.
At an elevation of 5,983 feet, Custer County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.
Custer County Soil Profile
Soil Type
Loam
Soil pH
6.5-8.1
Drainage
Well Drained
Plant Planting Risk Windows
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
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Pumpkin Planting Timeline — Custer County, MT
Pumpkin Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 2 | Apr 2 – Apr 16 |
| Transplant Outdoors | June 4 | Jun 4 – Jun 18 |
| Direct Sow | May 28 | May 28 – Jun 18 |
| Harvest | September 3 | Sep 3 – Oct 22 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | — |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
85–120 days
Soil pH
6 – 7.5
USDA Zone
Zone 4a
Growing Season
136 days
Growing Tips for Custer 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
Level Up Your Garden
Pumpkin in Other Locations
Frequently Asked Questions
When should I plant Pumpkin in Custer County, MT?
Custer County is in Zone 4a with an average last frost of May 14. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.
What planting zone is Custer County, MT?
Custer County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 27.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Custer County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.
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