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When to plant Geraniums in Power County, ID

Plant Geraniums in Power County during the brief May 18–June 1 window. With 142 frost-free days, fall plantings can't mature before September 30.

When to Plant Geraniums in Power County, ID

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.

Power County, Idaho is in USDA Zone 6a. The average last spring frost is May 11 and the first fall frost is September 30, giving you a growing season of approximately 142 days.

At an elevation of 6,609 feet, Power County receives approximately 14 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Geraniums during the growing season. 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
Power County, ID (Zone 6a) Short season
142 days
Last Spring Frost May 11
142 growing days
First Fall Frost September 30

Power County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.2

Drainage

Well Drained

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" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 4.3" 1.7" 2.6" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 1.5" 2.8" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Geraniums Planting Timeline — Power County, ID

Geraniums Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors May 18 May 18 – Jun 1
Bloom July 27 Jul 27 – Oct 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

142 days in Power County

Growing Tips for Power County

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 →

Frequently Asked Questions

When should I plant Geraniums in Power County, ID?

Power County is in Zone 6a with an average last frost of May 11. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Power County, ID?

Power County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 11 and first fall frost is September 30.

When should I plant Geraniums in Power County, ID?

In Power County, ID, plant Geraniums after the last frost (around May 11) and before the first frost (around September 30). Best results when soil holds above 50°F.

What growing zone is Power County, ID for Geraniums?

Power County sits in USDA Zone 6a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Power County's climate?

Yes — Geraniums grows well in Power County's temperate climate. Power County averages a 142-day frost-free season, with last frost around May 11 and first frost around September 30.

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Your Power County Garden Planner — Free

A 22-page printable planner built for Power 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 Power County, ID. Local conditions may vary. Last updated: July 2026.

Sources & credits

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