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When to Plant Geraniums in Crook County, WY

Crook County, Wyoming Zone 4b June

June in the garden — Crook County, Wyoming

Welcome to June in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 14
Avg. first frost October 1
Soil temp (4") 39°F
Watering High
Pest pressure High
Daylight 15.4 hrs
Looking ahead to 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.

Crook County, Wyoming is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is October 1, giving you a growing season of approximately 140 days.

At an elevation of 8,060 feet, Crook County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Geraniums to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Crook County, WY (Zone 4b) Short season
140 days
Last Spring Frost May 14
140 growing days
First Fall Frost October 1

Crook 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: Feb 21 Transplant: May 16 🌸 Bloom: Jul 25 – Oct 3
Recommended (50%) ✗ May not fit
Start indoors: Feb 26 Transplant: May 21 🌸 Bloom: Jul 30 – Oct 8
Safe Start (90%) ✗ May not fit
Start indoors: Mar 13 Transplant: Jun 5 🌸 Bloom: Aug 14 – Oct 23

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 Crook 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 Crook 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 140-day season

Sow every 8 weeks. Last sowing by Jun 23 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 383 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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 4.3" 3.1" 1.2" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Crook 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 ~978 GDD — county provides 1,610 GDD Excellent fit

Geraniums Planting Timeline — Crook County, WY

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 21 May 21 – Jun 4
Bloom July 30 Jul 30 – Oct 8

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 Transplant Outdoors
July Bloom
August Bloom
September Bloom
October Bloom
November
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 4b

📆 Growing Season

140 days in Crook County

Growing Tips for Geraniums in Crook County

Direct sow Geraniums outdoors after May 14 in Crook County when soil has warmed and frost danger has passed.

Crook County receives only 25" 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 Crook County, WY?

Crook County is in Zone 4b with an average last frost of May 14. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Crook County, WY?

Crook County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is October 1.

🌱

Your Crook County Garden Planner — Free

A 22-page printable planner built for Crook County (Zone 4b). 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 Crook County, WY. 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.