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When to plant Geraniums in Proberta,

Plant Geraniums in Proberta during the brief February 6–February 20 window. With 267 frost-free days, fall plantings can't mature before November 28.

When to Plant Geraniums in Proberta, CA

Proberta, CA Zone 9b June

Your June game plan for Proberta, CA

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

Avg. last frost March 6
Avg. first frost November 28
Soil temp (4") 81°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs
  1. Start harvesting geraniums

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Before July arrives, get these ready
  • 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.

Proberta, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 78 feet, Tehama County receives approximately 44 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
Proberta, CA (Zone 9b) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28
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Proberta Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Dec 15 Transplant: Jan 26 🌸 Bloom: Apr 6 – Oct 19
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Dec 26 Transplant: Feb 6 🌸 Bloom: Apr 17 – Oct 30
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Feb 7 Transplant: Mar 21 🌸 Bloom: May 30 – Dec 12

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 Proberta

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

Soil pH

Your soil pH (6.8–7.6) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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 267-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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 878 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 10.2" 0" ❄️ Dormant
Feb 8.5" 0" ❄️ Dormant
Mar 4.3" 7" 0" ✅ Rainfall sufficient
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 1.3" 3" 🚿 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" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 6.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tehama 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 3,070 GDD Excellent fit

Geraniums Planting Timeline — Proberta, CA

Geraniums Planting Calendar

Activity When Date Range
Start Indoors December 26 Dec 26 – Jan 9
Transplant Outdoors February 6 Feb 6 – Feb 20
Bloom April 17 Apr 17 – Oct 30

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
March
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December Start Indoors
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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 9b

📆 Growing Season

267 days in Tehama County

Growing Tips for Geraniums in Proberta

Direct sow Geraniums outdoors after March 06 in Tehama 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 →

When should I plant Geraniums in Proberta, ?

In Proberta, , plant Geraniums after the last frost (around March 6) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Proberta, for Geraniums?

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

Can Geraniums grow in Proberta's climate?

Yes — Geraniums grows well in Proberta's temperate climate. Proberta averages a 267-day frost-free season, with last frost around March 6 and first frost around November 28.

🌱

Your Tehama County Garden Planner — Free

A 22-page printable planner built for Tehama 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 Tehama County, CA. Local conditions may vary. Last updated: June 2026.