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When to plant Geraniums in Dutton, MT

Dutton sits in cold Zone 4b. Plant Geraniums June 1–June 15 for the single annual harvest; the September 16 first frost closes the window.

When to Plant Geraniums in Dutton, MT

Teton County, Montana Zone 4b July

This month in Teton County, Montana

Your Teton County, Montana garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost May 25
Avg. first frost September 16
Soil temp (4") 47°F
Watering High
Pest pressure High
Daylight 15.4 hrs
Looking ahead to August
  • Starting indoors: geraniums
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

Dutton, Montana is in USDA Zone 4b. The average last spring frost is May 25 and the first fall frost is September 16, giving you a growing season of approximately 114 days.

At an elevation of 8,276 feet, Teton County receives approximately 15.1 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Geraniums to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Geraniums successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Dutton, MT (Zone 4b) Short season
114 days
Last Spring Frost May 25
114 growing days
First Fall Frost September 16

Dutton Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 4 Transplant: May 27 🌸 Bloom: Aug 5 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Mar 9 Transplant: Jun 1 🌸 Bloom: Aug 10 – Oct 19
Safe Start (90%) ✗ May not fit
Start indoors: Mar 26 Transplant: Jun 18 🌸 Bloom: Aug 27 – Nov 5

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 Dutton

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

Soil pH

Your soil pH (6.6–7.6) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Geraniums.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Geraniums.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 905 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Geraniums

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

Month Geraniums Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 1.7" 2.6" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Geraniums 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.

Geraniums needs ~1,105 GDD — county provides 1,482 GDD Excellent fit

Geraniums Planting Timeline — Dutton, MT

Geraniums Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors June 1 Jun 1 – Jun 15
Bloom August 10 Aug 10 – Oct 19

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

114 days in Teton County

Growing Tips for Geraniums in Dutton

Direct sow Geraniums outdoors after May 25 in Teton County when soil has warmed and frost danger has passed.

Teton County receives only 15" of rain annually. Geraniums needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

When should I plant Geraniums in Dutton, MT?

In Dutton, MT, plant Geraniums after the last frost (around May 25) and before the first frost (around September 16). Best results when soil holds above 50°F.

What growing zone is Dutton, MT for Geraniums?

Dutton sits in USDA Zone 4b. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Dutton's climate?

Yes — Geraniums grows well in Dutton's temperate climate. Dutton averages a 114-day frost-free season, with last frost around May 25 and first frost around September 16.

🌱

Your Teton County Garden Planner — Free

A 22-page printable planner built for Teton County (Zone 4b). 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 Teton County, MT. Local conditions may vary. Last updated: July 2026.