Blog

When to Plant Geraniums in Keizer, OR

Keizer, OR Zone 8b June

June to-do list for Keizer, OR

We've pulled the most time-sensitive tasks for Keizer, OR this June and put them front and centre. Tackle them in order.

Avg. last frost April 20
Avg. first frost October 30
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.4 hrs
  1. Fire up the seed-starting tray: geraniums

    Label every cell. You will absolutely forget which is which otherwise.

  2. Pick geraniums

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July prep starts now
  • First harvests: geraniums

Instant PDF download. No spam, unsubscribe any time.

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.

Keizer, Oregon is in USDA Zone 8b. The average last spring frost is April 20 and the first fall frost is October 30, giving you a growing season of approximately 193 days.

At an elevation of 422 feet, Marion County receives approximately 50.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Geraniums during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Geraniums root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Keizer, OR (Zone 8b) Moderate season
193 days
Last Spring Frost April 20
193 growing days
First Fall Frost October 30

Keizer Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 2 Transplant: Mar 30 🌸 Bloom: Jun 8 – Nov 9
Recommended (50%) ✗ May not fit
Start indoors: Feb 9 Transplant: Apr 6 🌸 Bloom: Jun 15 – Nov 16
Safe Start (90%) ✗ May not fit
Start indoors: Feb 28 Transplant: Apr 25 🌸 Bloom: Jul 4 – Dec 5

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 Keizer

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — Geraniums will thrive.

How to Plant Geraniums

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

Succession Planting Geraniums

3
successive plantings in your 193-day season

Sow every 8 weeks. Last sowing by Jul 22 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 6.9" 0" ❄️ Dormant
Feb 5.1" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 2" 2.3" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 1" 3.3" 🚿 Regular watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 8.2" 0" ❄️ Dormant
Dec 9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Marion 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 ~1,360 GDD — county provides 3,088 GDD Excellent fit

Geraniums Planting Timeline — Keizer, OR

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 – Feb 23
Transplant Outdoors April 6 Apr 6 – Apr 20
Bloom June 15 Jun 15 – Nov 16

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors
May
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

193 days in Marion County

Growing Tips for Geraniums in Keizer

Direct sow Geraniums outdoors after April 20 in Marion County when soil has warmed and frost danger has passed.

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 →

🌱

Your Marion County Garden Planner — Free

A 22-page printable planner built for Marion County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Marion County, OR. Local conditions may vary. Last updated: June 2026.