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When to plant Geraniums in Archuleta County, CO

Archuleta County's short 96-day growing season means one Geraniums planting between June 20 and July 4. No fall crop in Zone 5b.

When to Plant Geraniums in Archuleta County, CO

Archuleta County, Colorado Zone 5b June

Your June gardening checklist

A quick June briefing for Archuleta County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost June 13
Avg. first frost September 17
Soil temp (4") 56°F
Watering Critical
Pest pressure High
Daylight 14.5 hrs
  1. Set out geraniums seedlings

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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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.

Archuleta County, Colorado is in USDA Zone 5b. The average last spring frost is June 13 and the first fall frost is September 17, giving you a growing season of approximately 96 days.

At an elevation of 5,346 feet, Archuleta County receives approximately 14 inches of rainfall annually with predominantly loam soil. Summer highs average 85°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
Archuleta County, CO (Zone 5b) Very short season
96 days
Last Spring Frost June 13
96 growing days
First Fall Frost September 17

Archuleta County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 28 Transplant: Jun 13 🌸 Bloom: Aug 22 – Nov 14
Recommended (50%) ✗ May not fit
Start indoors: Apr 4 Transplant: Jun 20 🌸 Bloom: Aug 29 – Nov 21
Safe Start (90%) ✗ May not fit
Start indoors: Apr 15 Transplant: Jul 1 🌸 Bloom: Sep 9 – Dec 2

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 Archuleta County

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

Soil pH

Your soil pH (6.3–7.9) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Archuleta 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
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 397 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 0.9" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.9" 0" ❄️ Dormant
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.3" 3" 🚿 Regular watering
Aug 4.3" 1.3" 3" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 1.1" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Archuleta 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 ~1,169 GDD — county provides 1,320 GDD Good fit

Geraniums Planting Timeline — Archuleta County, CO

Geraniums Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors June 20 Jun 20 – Jul 4
Bloom August 29 Aug 29 – Nov 21

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 Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

96 days in Archuleta County

Growing Tips for Geraniums in Archuleta County

Direct sow Geraniums outdoors after June 13 in Archuleta County when soil has warmed and frost danger has passed.

Your 96.0-day growing season in Archuleta County is tight for Geraniums (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

Archuleta 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 Archuleta County, CO?

Archuleta County is in Zone 5b with an average last frost of June 13. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Archuleta County, CO?

Archuleta County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 13 and first fall frost is September 17.

When should I plant Geraniums in Archuleta County, CO?

In Archuleta County, CO, plant Geraniums after the last frost (around June 13) and before the first frost (around September 17). Best results when soil holds above 50°F.

What growing zone is Archuleta County, CO for Geraniums?

Archuleta 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 Archuleta County's climate?

Yes — Geraniums grows well in Archuleta County's temperate climate. Archuleta County averages a 96-day frost-free season, with last frost around June 13 and first frost around September 17.

🌱

Your Archuleta County Garden Planner — Free

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

Sources & credits

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