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When to plant Geraniums in Comptche, CA

In Comptche, Geraniums is a spring-only crop. Plant February 23–March 9 once soil hits 50°F.

When to Plant Geraniums in Comptche, CA

Mendocino County, California Zone 9b June

June in the garden — Mendocino County, California

A quick June briefing for Mendocino County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 23
Avg. first frost November 9
Soil temp (4") 84°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs
  1. Get geraniums seeds going inside

    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. Bring in the geraniums

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

Coming up in July — start thinking about
  • 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.

Comptche, California is in USDA Zone 9b. The average last spring frost is March 23 and the first fall frost is November 9, giving you a growing season of approximately 231 days.

At an elevation of 180 feet, Mendocino County receives approximately 24 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
Comptche, CA (Zone 9b) Long season
231 days
Last Spring Frost March 23
231 growing days
First Fall Frost November 9

Comptche Soil Profile

Soil Type

Sandy Loam

Soil pH

6.1-7.2

Drainage

Well Drained

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 5.2" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 1.9" 2.4" 🚿 Regular watering
May 4.3" 0.6" 3.7" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 1" 3.3" 🚿 Regular watering
Nov 4.3" 2.6" 1.7" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Mendocino County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Geraniums Planting Timeline — Comptche, CA

Geraniums Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 – Jan 26
Transplant Outdoors February 23 Feb 23 – Mar 9
Bloom May 4 May 4 – Nov 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

231 days in Mendocino County

Growing Tips for Comptche

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 Comptche, CA?

In Comptche, CA, plant Geraniums after the last frost (around March 23) and before the first frost (around November 9). Best results when soil holds above 50°F.

What growing zone is Comptche, CA for Geraniums?

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

Can Geraniums grow in Comptche's climate?

Yes — Geraniums grows well in Comptche's temperate climate. Comptche averages a 231-day frost-free season, with last frost around March 23 and first frost around November 9.

🌱

Your Mendocino County Garden Planner — Free

A 22-page printable planner built for Mendocino 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.

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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 Mendocino County, CA. Local conditions may vary. Last updated: June 2026.