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When to Plant Raspberries in Lewis and Clark County, MT

Raspberries are beloved bramble fruits producing sweet, delicate berries in red, golden, black, and purple varieties. They spread by underground runners and are very productive.

Lewis and Clark County, Montana is in USDA Zone 4b. The average last spring frost is May 29 and the first fall frost is September 18, giving you a growing season of approximately 112 days.

At an elevation of 7,064 feet, Lewis and Clark County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Raspberries to ensure they mature before fall.

Lewis and Clark County, MT (Zone 4b) Short season
112 days
Last Spring Frost May 29
112 growing days
First Fall Frost September 18

Lewis and Clark County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 15
Recommended (50%) ✓ Fits season
Transplant: Jun 26
Safe Start (90%) ✓ Fits season
Transplant: Jul 17

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
0.2″/week
Watering frequency Only during dry spells
Season total 200 gal / 100 sq ft
Drought risk

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

Raspberries needs ~6,296 GDD — county provides 1,288 GDD May not mature

Raspberries Planting Timeline โ€” Lewis and Clark County, MT

Raspberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 26 Jun 26 โ€“ Jul 10

ยท 24" apart ยท Rows 72" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

365โ€“730 days

Soil pH

5.5 โ€“ 6.5

USDA Zone

Zone 4b

Growing Season

112 days

Growing Tips for Lewis and Clark County

Provide a trellis for support. Prune summer-bearing types by removing spent canes after harvest. For ever-bearing types, mow all canes in late winter for a single fall crop.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Tomatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Raspberries in Lewis and Clark County, MT?

Lewis and Clark County is in Zone 4b with an average last frost of May 29. Plan your Raspberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lewis and Clark County, MT?

Lewis and Clark County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 29 and first fall frost is September 18.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Lewis and Clark County, MT. Local conditions may vary. Last updated: April 2026.