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When to plant Hydrangeas in Beaverhead County, MT

In Beaverhead County, Hydrangeas is a single-season spring crop — there's no second fall window. Plant June 24–July 8 for an 90–150-day harvest, finishing well before the September 12 first frost.

When to Plant Hydrangeas in Beaverhead County, MT

Hydrangeas (Hydrangea spp.) are among the most spectacular summer-blooming shrubs, with large mophead, lacecap, or panicle flower clusters lasting weeks in the garden and drying beautifully for arrangements. Native to Asia and North America alike, the genus spans several garden species with different hardiness and blooming habits. Panicle hydrangeas (H. paniculata, e.g., Limelight) are the most cold-hardy (Zone 3) and most reliable bloomers; smooth hydrangeas (H. arborescens, e.g., Annabelle) are equally tough. Bigleaf hydrangeas (H. macrophylla) are prized for blue/pink color-shifting blooms but require reliable snow cover or winter protection in Zones 5–6. Flower color in macrophylla types is determined by soil pH (acidic = blue, alkaline = pink).

Beaverhead County, Montana is in USDA Zone 5a. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.

At an elevation of 7,645 feet, Beaverhead County receives approximately 15.7 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Hydrangeas to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Hydrangeas successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Beaverhead County, MT (Zone 5a) Very short season
94 days
Last Spring Frost June 10
94 growing days
First Fall Frost September 12

Beaverhead County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Monthly Watering Guide for Hydrangeas

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

Month Hydrangeas Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 1.9" 0" ❄️ Dormant
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.3" 3" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Hydrangeas Planting Timeline — Beaverhead County, MT

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors June 24 Jun 24 – Jul 8
Bloom September 9 Sep 9 – Nov 25

Plant 1" deep · 48" apart · Rows 60" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May
June Transplant Outdoors
July Transplant Outdoors
August
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

94 days in Beaverhead County

Growing Tips for Beaverhead County

Plant container-grown specimens in spring or fall, spacing at least 3–5 feet apart to allow for mature shrub spread. Most hydrangeas prefer morning sun with afternoon shade, especially in Zones 7+. Keep consistently moist — the name derives from the Greek for water vessel. Prune panicle and smooth types in late winter/early spring (they bloom on new wood). Prune bigleaf types only lightly after bloom; cutting stems in fall removes next year's buds. In Zone 5–6, protect bigleaf varieties with burlap or wire cages filled with leaves over winter. Fall planting (Zones 5+) gives excellent root establishment before summer heat. Year 2+ plants reach full size and bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hydrangeas in Beaverhead County, MT?

Beaverhead County is in Zone 5a with an average last frost of June 10. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Beaverhead County, MT?

Beaverhead County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 10 and first fall frost is September 12.

When should I plant Hydrangeas in Beaverhead County, MT?

In Beaverhead County, MT, plant Hydrangeas after the last frost (around June 10) and before the first frost (around September 12). Best results when soil holds above 50°F.

What growing zone is Beaverhead County, MT for Hydrangeas?

Beaverhead County sits in USDA Zone 5a. Hydrangeas grows reliably in zones 3a through 9a, so it's a good fit here.

Can Hydrangeas grow in Beaverhead County's climate?

Yes — Hydrangeas grows well in Beaverhead County's temperate climate. Beaverhead County averages a 94-day frost-free season, with last frost around June 10 and first frost around September 12.

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Your Beaverhead County Garden Planner — Free

A 22-page printable planner built for Beaverhead County (Zone 5a). 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 Beaverhead County, MT. Local conditions may vary. Last updated: July 2026.

Sources & credits

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