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When to Plant Geraniums in Crook County, OR

Crook County, Oregon Zone 6a August

Your August game plan for Crook County, Oregon

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

Avg. last frost June 9
Avg. first frost September 19
Soil temp (4") 77°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. Fire up the seed-starting tray: geraniums

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Start harvesting geraniums

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

September prep starts now
  • 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, Oregon is in USDA Zone 6a. The average last spring frost is June 9 and the first fall frost is September 19, giving you a growing season of approximately 102 days.

At an elevation of 2,233 feet, Crook County receives approximately 21 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Geraniums during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Crook County, OR (Zone 6a) Short season
102 days
Last Spring Frost June 9
102 growing days
First Fall Frost September 19

Crook County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 21 Transplant: Jun 6 🌸 Bloom: Aug 15 – Nov 14
Recommended (50%) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 16 🌸 Bloom: Aug 25 – Nov 24
Safe Start (90%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jun 29 🌸 Bloom: Sep 7 – Dec 7

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 (5.7–6.7) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.6%) — Geraniums will thrive.

How to Plant Geraniums

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

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 147 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 3.4" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 1.2" 0" ❄️ Dormant
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 1" 3.3" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 3.1" 0" ❄️ Dormant
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep 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 ~1,169 GDD — county provides 1,402 GDD Good fit

Geraniums Planting Timeline — Crook County, OR

Geraniums Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors June 16 Jun 16 – Jun 30
Bloom August 25 Aug 25 – Nov 24

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

Month-by-Month Timeline

MonthActivities
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 · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

102 days in Crook County

Growing Tips for Geraniums in Crook County

Direct sow Geraniums outdoors after June 09 in Crook County when soil has warmed and frost danger has passed.

Your 102.0-day growing season in Crook County is tight for Geraniums (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

Crook County receives only 21" 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, OR?

Crook County is in Zone 6a with an average last frost of June 9. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Crook County, OR?

Crook County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 9 and first fall frost is September 19.

🌱

Your Crook County Garden Planner — Free

A 22-page printable planner built for Crook 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 Crook County, OR. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.