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When to Plant Blueberries in Lake County, MT

Lake County, Montana Zone 6a May

May to-do list for Lake County, Montana

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Lake County, Montana.

Avg. last frost May 31
Avg. first frost September 12
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
June will be here before you know it — start on
  • Transplants going out: blueberries

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Blueberries are long-lived shrubs producing sweet, antioxidant-rich berries. They require acidic soil and are attractive ornamental plants with fall color and spring flowers.

Lake County, Montana is in USDA Zone 6a. The average last spring frost is May 31 and the first fall frost is September 12, giving you a growing season of approximately 104 days.

At an elevation of 6,938 feet, Lake County receives approximately 12.8 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Blueberries during the growing season. With low rainfall, drip irrigation is essential for growing Blueberries successfully. Mulch heavily to conserve soil moisture.

Lake County, MT (Zone 6a) Short season
104 days
Last Spring Frost May 31
104 growing days
First Fall Frost September 12

Lake County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 10
Recommended (50%) ✓ Fits season
Transplant: Jun 21
Safe Start (90%) ✓ Fits season
Transplant: Jul 12

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 Lake County

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Blueberries prefers (4.5–5.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Blueberries.

How to Plant Blueberries

48"
Between Plants
72"
Between Rows

How Much Blueberries to Grow

5-10 lbs
Average yield per plant
2
Plants per person
48 sq ft
Space per person

For a family of 4, plant approximately 8 blueberries plants in about 192 sq ft. In Lake County's 104-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.5″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 759 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Blueberries

Blueberries needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Blueberries Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 5.2" 1.4" 3.8" 🚿 Regular watering
Jun 5.2" 0.9" 4.3" 🚿 Regular watering
Jul 5.2" 1.3" 3.9" 🚿 Regular watering
Aug 5.2" 1.2" 4" 🚿 Regular watering
Sep 5.2" 1.1" 4.1" 🚿 Regular watering
Oct 1.1" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Blueberries 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.

Blueberries needs ~12,547 GDD — county provides 1,430 GDD May not mature

Blueberries Planting Timeline — Lake County, MT

Blueberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 21 Jun 21 – Jul 5

· 48" 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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 2-3 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 4.5–5.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

104 days in Lake County

Growing Tips for Blueberries in Lake County

Direct sow Blueberries outdoors after May 31 in Lake County when soil has warmed and frost danger has passed.

Your 104.0-day growing season in Lake County is tight for Blueberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

Lake County receives only 13" of rain annually. Blueberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant at least two varieties for cross-pollination. Acidify soil with sulfur or pine needle mulch to maintain pH 4.5-5.5. Protect ripening berries from birds with netting.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Blueberries in Lake County, MT?

Lake County is in Zone 6a with an average last frost of May 31. Plan your Blueberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, MT?

Lake County, Montana is in USDA Hardiness Zone 6a. The average last spring frost is May 31 and first fall frost is September 12.

🌱

Your Lake County Garden Planner — Free

A 24-page printable planner built for Lake County (Zone 6a). 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 Lake County, MT. Local conditions may vary. Last updated: May 2026.

Sources & credits

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