When to plant Geraniums in Silver Bow County, MT
Plant Geraniums in Silver Bow County, between June 22 and July 6 — the only viable window. Zone 5a's short season (84 frost-free days) rules out a fall crop.
When to Plant Geraniums in Silver Bow County, MT
Your June game plan for Silver Bow County, Montana
Your garden in Silver Bow County, Montana is working on a schedule, even when you're not. Here's where you should be this June.
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Transplant geraniums outside
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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.
Silver Bow County, Montana is in USDA Zone 5a. The average last spring frost is June 15 and the first fall frost is September 7, giving you a growing season of approximately 84 days.
At an elevation of 5,305 feet, Silver Bow County receives approximately 14.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Geraniums to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Geraniums successfully. Mulch heavily to conserve soil moisture.
Silver Bow County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.3
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 Silver Bow County
How your county's soil matches Geraniums's growing requirements.
Soil pH
Your soil pH (6.6–8.3) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Silver Bow 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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | — | 1.5" | 0" | ❄️ Dormant |
| Jun | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jul | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Aug | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Sep | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Oct | — | 1.1" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Silver Bow 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 — Silver Bow County, MT
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | June 22 | Jun 22 – Jul 6 |
| Bloom | August 31 | Aug 31 – Nov 23 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 5a
📆 Growing Season
84 days in Silver Bow County
Growing Tips for Geraniums in Silver Bow County
Direct sow Geraniums outdoors after June 15 in Silver Bow County when soil has warmed and frost danger has passed.
Your 84.0-day growing season in Silver Bow County is tight for Geraniums (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.
Silver Bow 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 →
Geraniums in Other Locations
Frequently Asked Questions
When should I plant Geraniums in Silver Bow County, MT?
Silver Bow County is in Zone 5a with an average last frost of June 15. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Silver Bow County, MT?
Silver Bow County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 15 and first fall frost is September 7.
When should I plant Geraniums in Silver Bow County, MT?
In Silver Bow County, MT, plant Geraniums after the last frost (around June 15) and before the first frost (around September 7). Best results when soil holds above 50°F.
What growing zone is Silver Bow County, MT for Geraniums?
Silver Bow County sits in USDA Zone 5a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.
Can Geraniums grow in Silver Bow County's climate?
Yes — Geraniums grows well in Silver Bow County's temperate climate. Silver Bow County averages a 84-day frost-free season, with last frost around June 15 and first frost around September 7.
Your Silver Bow County Garden Planner — Free
A 22-page printable planner built for Silver Bow County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.