Blog

When to plant Geraniums in Samoa, CA

In Samoa, Geraniums is a single-season spring crop — there's no second fall window. Plant January 30–February 13 for an 70–100-day harvest, finishing well before the November 28 first frost.

When to Plant Geraniums in Samoa, CA

Humboldt County, California Zone 9b July

Humboldt County, California gardeners: here's your July plan

Your garden in Humboldt County, California is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost February 27
Avg. first frost November 28
Soil temp (4") 92°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Harvest geraniums as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

August 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.

Samoa, California is in USDA Zone 9b. The average last spring frost is February 27 and the first fall frost is November 28, giving you a growing season of approximately 274 days.

At an elevation of 148 feet, Humboldt County receives approximately 22.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Geraniums during the growing season. Sandy soil warms quickly in spring — great for early planting — but Geraniums will need more frequent watering and organic matter to retain nutrients.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Samoa, CA (Zone 9b) Year-round
274 days
Last Spring Frost February 27
274 growing days
First Fall Frost November 28

Samoa Soil Profile

Soil Type

Sandy Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Start indoors: Dec 5 Transplant: Jan 16 🌸 Bloom: Mar 27 – Oct 9
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Dec 19 Transplant: Jan 30 🌸 Bloom: Apr 10 – Oct 23
Safe Start (90%) ✓ Fits season (22 days to spare)
Start indoors: Jan 22 Transplant: Mar 5 🌸 Bloom: May 14 – Nov 26

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 Samoa

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

Soil pH

Your soil pH (6.2–6.8) is within Geraniums's preferred range (6.0–7.0).

Soil Texture

Sandy soil in Humboldt County warms quickly in spring but drains fast. Geraniums will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Geraniums.

How to Plant Geraniums

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

Succession Planting Geraniums

4
successive plantings in your 274-day season

Sow every 8 weeks. Last sowing by Aug 20 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,621 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 4.8" 0" ❄️ Dormant
Feb 4.3" 5" 0" ✅ Rainfall sufficient
Mar 4.3" 3.3" 1" 💧 Light watering
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 0.8" 3.5" 🚿 Regular watering
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Humboldt 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 ~1,296 GDD — county provides 4,193 GDD Excellent fit

Geraniums Planting Timeline — Samoa, CA

Geraniums Planting Calendar

Activity When Date Range
Start Indoors December 19 Dec 19 – Jan 2
Transplant Outdoors January 30 Jan 30 – Feb 13
Bloom April 10 Apr 10 – Oct 23

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

Month-by-Month Timeline

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

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: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

274 days in Humboldt County

Growing Tips for Geraniums in Samoa

Direct sow Geraniums outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.

Sandy soil in Humboldt County dries quickly — mulch Geraniums with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Humboldt County receives only 22" 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 →

When should I plant Geraniums in Samoa, CA?

In Samoa, CA, plant Geraniums after the last frost (around February 27) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Samoa, CA for Geraniums?

Samoa sits in USDA Zone 9b. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Samoa's climate?

Yes — Geraniums grows well in Samoa's temperate climate. Samoa averages a 275-day frost-free season, with last frost around February 27 and first frost around November 28.

🌱

Your Humboldt County Garden Planner — Free

A 22-page printable planner built for Humboldt County (Zone 9b). 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 Humboldt County, CA. Local conditions may vary. Last updated: July 2026.