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When to Plant Raspberries in Fergus County, MT

Fergus County, Montana Zone 4a April

What to do in April

Your garden in Fergus County, Montana is working on a schedule, even when you're not. Here's where you should be this April.

Avg. last frost May 20
Avg. first frost September 20
Soil temp (4") 21°F
Watering High
Pest pressure Low
Daylight 13.4 hrs

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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.

Fergus County, Montana is in USDA Zone 4a. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.

At an elevation of 6,957 feet, Fergus County receives approximately 12 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Raspberries to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Raspberries successfully. Mulch heavily to conserve soil moisture.

Fergus County, MT (Zone 4a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20
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Fergus County Soil Profile

Soil Type

Loam

Soil pH

6.4-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 11
Recommended (50%) ✓ Fits season
Transplant: Jun 17
Safe Start (90%) ✓ Fits season
Transplant: Jul 4

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 Fergus County

How your county's soil matches Raspberries's growing requirements.

Soil pH

Your soil pH (6.4–8.0) is more alkaline than Raspberries prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Fergus County is excellent for Raspberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Raspberries.

How to Plant Raspberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 775 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Raspberries

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

Month Raspberries Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 0.7" 3.6" 🚿 Regular watering
Jul 4.3" 1.1" 3.2" 🚿 Regular watering
Aug 4.3" 1.3" 3" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Raspberries 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.

Raspberries needs ~5,475 GDD — county provides 1,230 GDD May not mature

Raspberries Planting Timeline — Fergus County, MT

Raspberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 17 Jun 17 – Jul 1

· 24" apart · Rows 72" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July Transplant Outdoors
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

123 days in Fergus County

Growing Tips for Raspberries in Fergus County

Direct sow Raspberries outdoors after May 20 in Fergus County when soil has warmed and frost danger has passed.

Your 123.0-day growing season in Fergus County is tight for Raspberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Fergus County receives only 12" of rain annually. Raspberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Raspberries in Fergus County, MT?

Fergus County is in Zone 4a with an average last frost of May 20. Plan your Raspberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fergus County, MT?

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

🌱

Your Fergus County Garden Planner — Free

A 24-page printable planner built for Fergus County (Zone 4a). 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 Fergus County, MT. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.