When to plant Geraniums in Rio Blanco County, CO
Plant Geraniums in Rio Blanco County during the brief June 9–June 23 window. With 107 frost-free days, fall plantings can't mature before September 17.
When to Plant Geraniums in Rio Blanco County, CO
June to-do list for Rio Blanco County, Colorado
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Rio Blanco County, Colorado.
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Move geraniums from tray to bed
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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.
Rio Blanco County, Colorado is in USDA Zone 5b. The average last spring frost is June 2 and the first fall frost is September 17, giving you a growing season of approximately 107 days.
At an elevation of 6,974 feet, Rio Blanco County receives approximately 19 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.
Rio Blanco County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.7
Drainage
Well Drained
Geraniums Planting Risk Windows
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 Rio Blanco County
How your county's soil matches Geraniums's growing requirements.
Soil pH
Your soil pH (6.4–7.7) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Rio Blanco County is excellent for Geraniums — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Geraniums.
How to Plant Geraniums
Geraniums Water Budget
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | — | 2.1" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.5" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Rio Blanco 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 Planting Timeline — Rio Blanco County, CO
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 24 | Mar 24 – Apr 7 |
| Transplant Outdoors | June 9 | Jun 9 – Jun 23 |
| Bloom | August 18 | Aug 18 – Nov 10 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | — |
| June | Transplant Outdoors |
| July | — |
| 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
107 days in Rio Blanco County
Growing Tips for Geraniums in Rio Blanco County
Direct sow Geraniums outdoors after June 02 in Rio Blanco County when soil has warmed and frost danger has passed.
Your 107.0-day growing season in Rio Blanco County is tight for Geraniums (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.
Rio Blanco 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 →
Geraniums in Other Locations
Frequently Asked Questions
When should I plant Geraniums in Rio Blanco County, CO?
Rio Blanco County is in Zone 5b with an average last frost of June 2. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Rio Blanco County, CO?
Rio Blanco County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 2 and first fall frost is September 17.
When should I plant Geraniums in Rio Blanco County, CO?
In Rio Blanco County, CO, plant Geraniums after the last frost (around June 2) and before the first frost (around September 17). Best results when soil holds above 50°F.
What growing zone is Rio Blanco County, CO for Geraniums?
Rio Blanco 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 Rio Blanco County's climate?
Yes — Geraniums grows well in Rio Blanco County's temperate climate. Rio Blanco County averages a 107-day frost-free season, with last frost around June 2 and first frost around September 17.
Your Rio Blanco County Garden Planner — Free
A 22-page printable planner built for Rio Blanco 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.