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When to plant Geraniums in Pueblo County, CO

In Pueblo County, Geraniums is a single-season spring crop — there's no second fall window. Plant May 14–May 28 for an 70–100-day harvest, finishing well before the October 7 first frost.

When to Plant Geraniums in Pueblo County, CO

Pueblo County, Colorado Zone 6a June

Pueblo County, Colorado gardeners: here's your June plan

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 7
Avg. first frost October 7
Soil temp (4") 62°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
Get ahead of July
  • 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.

Pueblo County, Colorado is in USDA Zone 6a. The average last spring frost is May 7 and the first fall frost is October 7, giving you a growing season of approximately 153 days.

At an elevation of 4,607 feet, Pueblo County receives approximately 14.1 inches of rainfall annually with predominantly loam soil. Summer highs average 88°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
Pueblo County, CO (Zone 6a) Moderate season
153 days
Last Spring Frost May 7
153 growing days
First Fall Frost October 7

Pueblo County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.9

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 19 Transplant: May 7 🌸 Bloom: Jul 16 – Oct 15
Recommended (50%) ✗ May not fit
Start indoors: Feb 26 Transplant: May 14 🌸 Bloom: Jul 23 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: Mar 11 Transplant: May 27 🌸 Bloom: Aug 5 – Nov 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 Pueblo County

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

Soil pH

Your soil pH (6.7–7.9) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Geraniums.

How to Plant Geraniums

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

Succession Planting Geraniums

2
successive plantings in your 153-day season

Sow every 8 weeks. Last sowing by Jun 29 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,002 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.1" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.1" 3.2" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Pueblo 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 ~1,360 GDD — county provides 2,448 GDD Excellent fit

Geraniums Planting Timeline — Pueblo County, CO

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 14 May 14 – May 28
Bloom July 23 Jul 23 – Oct 22

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors
June
July Bloom
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 6a

📆 Growing Season

153 days in Pueblo County

Growing Tips for Geraniums in Pueblo County

Direct sow Geraniums outdoors after May 07 in Pueblo County when soil has warmed and frost danger has passed.

Pueblo County receives only 14" 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 Pueblo County, CO?

Pueblo County is in Zone 6a with an average last frost of May 7. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pueblo County, CO?

Pueblo County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 7 and first fall frost is October 7.

When should I plant Geraniums in Pueblo County, CO?

In Pueblo County, CO, plant Geraniums after the last frost (around May 7) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Pueblo County, CO for Geraniums?

Pueblo 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 Pueblo County's climate?

Yes — Geraniums grows well in Pueblo County's temperate climate. Pueblo County averages a 153-day frost-free season, with last frost around May 7 and first frost around October 7.

🌱

Your Pueblo County Garden Planner — Free

A 22-page printable planner built for Pueblo 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 Pueblo 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.