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When to Plant Cranberries in Powder River County, MT

Cranberries are low-growing, vine-like shrubs that produce tart red berries in fall. They grow in acidic, boggy conditions and are surprisingly easy to cultivate.

Powder River County, Montana is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is September 22, giving you a growing season of approximately 130 days.

At an elevation of 6,328 feet, Powder River County receives approximately 19.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Cranberries to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cranberries successfully. Mulch heavily to conserve soil moisture.

Powder River County, MT (Zone 4a) Short season
130 days
Last Spring Frost May 15
130 growing days
First Fall Frost September 22

Powder River County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 8
Recommended (50%) ✓ Fits season
Transplant: Jun 12
Safe Start (90%) ✓ Fits season
Transplant: Jun 26

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
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,212 gal / 100 sq ft
Drought risk

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

Cranberries needs ~11,178 GDD — county provides 1,592 GDD May not mature

Cranberries Planting Timeline โ€” Powder River County, MT

Cranberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 12 Jun 12 โ€“ Jun 26

ยท 36" apart ยท Rows 48" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Transplant Outdoors
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

730โ€“1095 days

Soil pH

4 โ€“ 5.5

USDA Zone

Zone 4a

Growing Season

130 days

Growing Tips for Powder River County

Create an acidic, consistently moist bed with peat moss. Cranberries do not need to be flooded to grow; flooding is only used for commercial harvesting. Mulch with sand in early spring.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Cranberries in Powder River County, MT?

Powder River County is in Zone 4a with an average last frost of May 15. Plan your Cranberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Powder River County, MT?

Powder River County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is September 22.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Powder River County gardeners in Zone 4a 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 Powder River County, MT. Local conditions may vary. Last updated: April 2026.