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When to plant Geraniums in Eagle County County,

Eagle County County sits in cold Zone 5b. Plant Geraniums June 23–July 7 for the single annual harvest; the September 7 first frost closes the window.

When to Plant Geraniums in Eagle County, CO

Eagle County, Colorado Zone 5b June

June to-do list for Eagle County, Colorado

Here's what deserves your attention in Eagle County, Colorado this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost June 16
Avg. first frost September 7
Soil temp (4") 43°F
Watering High
Pest pressure High
Daylight 14.8 hrs
  1. Plant out geraniums

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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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.

Eagle County, Colorado is in USDA Zone 5b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,116 feet, Eagle County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Geraniums to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Eagle County, CO (Zone 5b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7
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Eagle County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 27 Transplant: Jun 12 🌸 Bloom: Aug 21 – Nov 13
Recommended (50%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 23 🌸 Bloom: Sep 1 – Nov 24
Safe Start (90%) ✗ May not fit
Start indoors: Apr 18 Transplant: Jul 4 🌸 Bloom: Sep 12 – Dec 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 Eagle County

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.8" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 3.2" 0" ❄️ Dormant
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.4" 1.9" 💧 Light watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Eagle 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 ~914 GDD — county provides 892 GDD Tight fit

Geraniums Planting Timeline — Eagle County, CO

Geraniums Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors June 23 Jun 23 – Jul 7
Bloom September 1 Sep 1 – Nov 24

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

83 days in Eagle County

Growing Tips for Geraniums in Eagle County

Direct sow Geraniums outdoors after June 16 in Eagle County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Eagle County is tight for Geraniums (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

Eagle County receives only 24" 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 →

Frequently Asked Questions

When should I plant Geraniums in Eagle County, CO?

Eagle County is in Zone 5b with an average last frost of June 16. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Eagle County, CO?

Eagle County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 16 and first fall frost is September 7.

When should I plant Geraniums in Eagle County County, ?

In Eagle County County, , plant Geraniums after the last frost (around June 16) and before the first frost (around September 7). Best results when soil holds above 50°F.

What growing zone is Eagle County County, for Geraniums?

Eagle County County sits in USDA Zone 5b. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Eagle County County's climate?

Yes — Geraniums grows well in Eagle County County's temperate climate. Eagle County County averages a 83-day frost-free season, with last frost around June 16 and first frost around September 7.

🌱

Your Eagle County Garden Planner — Free

A 22-page printable planner built for Eagle County (Zone 5b). 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 Eagle County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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