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When to plant Geraniums in Chaffee County County,

Chaffee County County's short 83-day growing season means one Geraniums planting between June 23 and July 7. No fall crop in Zone 5b.

When to Plant Geraniums in Chaffee County, CO

Chaffee County, Colorado Zone 5b June

This month in Chaffee County, Colorado

Your garden in Chaffee County, Colorado is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost June 16
Avg. first frost September 7
Soil temp (4") 47°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Set out geraniums seedlings

    Frost risk is low now in Chaffee County, Colorado. If you've been covering beds overnight, you can stop.

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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.

Chaffee 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 7,788 feet, Chaffee County receives approximately 18.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86°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
Chaffee County, CO (Zone 5b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Chaffee County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: Jun 17 🌸 Bloom: Aug 26 – Nov 18
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 17 Transplant: Jul 3 🌸 Bloom: Sep 11 – Dec 4

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 Chaffee County

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

Soil pH

Your soil pH (6.7–7.6) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 52 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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 2.4" 0" ❄️ Dormant
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Chaffee 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 ~1,232 GDD — county provides 1,203 GDD Tight fit

Geraniums Planting Timeline — Chaffee 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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

83 days in Chaffee County

Growing Tips for Geraniums in Chaffee County

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

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

Chaffee County receives only 19" 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 Chaffee County, CO?

Chaffee 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 Chaffee County, CO?

Chaffee 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 Chaffee County County, ?

In Chaffee 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 Chaffee County County, for Geraniums?

Chaffee 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 Chaffee County County's climate?

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

🌱

Your Chaffee County Garden Planner — Free

A 22-page printable planner built for Chaffee 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 Chaffee County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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