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When to plant Geraniums in Redding, CA

In Redding, Geraniums is a single-season spring crop — there's no second fall window. Plant May 16–May 30 for an 70–100-day harvest, finishing well before the September 21 first frost.

When to Plant Geraniums in Redding, CA

Shasta County, California Zone 9a June

What to do in June

Welcome to June in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost June 6
Avg. first frost September 21
Soil temp (4") 81°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
July will be here before you know it — start on
  • 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.

Redding, California is in USDA Zone 9a. The average last spring frost is June 6 and the first fall frost is September 21, giving you a growing season of approximately 107 days.

At an elevation of 81 feet, Shasta County receives approximately 40.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 85°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
Redding, CA (Zone 9a) Short season
107 days
Last Spring Frost June 6
107 growing days
First Fall Frost September 21

Redding Soil Profile

Soil Type

Sandy Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (247 days to spare)
Start indoors: Mar 14 Transplant: May 2 🌸 Bloom: Jul 11 – Jan 9
Recommended (50%) ✓ Fits season (241 days to spare)
Start indoors: Mar 28 Transplant: May 16 🌸 Bloom: Jul 25 – Jan 23
Safe Start (90%) ✓ Fits season (244 days to spare)
Start indoors: Apr 13 Transplant: Jun 1 🌸 Bloom: Aug 10 – Feb 8

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 Redding

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

Sandy soil in Shasta 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 (2.6%). Annual compost additions will help Geraniums.

How to Plant Geraniums

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

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
1.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 7.7" 0" ❄️ Dormant
Feb 8" 0" ❄️ Dormant
Mar 6.8" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 1" 0" ❄️ Dormant
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 1.6" 0" ❄️ Dormant
Nov 4.4" 0" ❄️ Dormant
Dec 7.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Shasta 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 1,471 GDD Good fit

Geraniums Planting Timeline — Redding, CA

Geraniums Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 16 May 16 – May 30
Bloom July 25 Jul 25 – Jan 23

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

Month-by-Month Timeline

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

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 9a

📆 Growing Season

107 days in Shasta County

Growing Tips for Geraniums in Redding

Direct sow Geraniums outdoors after June 06 in Shasta County when soil has warmed and frost danger has passed.

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

Your 107.0-day growing season in Shasta County is tight for Geraniums (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Redding, CA?

In Redding, CA, plant Geraniums after the last frost (around June 6) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Redding, CA for Geraniums?

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

Can Geraniums grow in Redding's climate?

Yes — Geraniums grows well in Redding's temperate climate. Redding averages a 107-day frost-free season, with last frost around June 6 and first frost around September 21.

🌱

Your Shasta County Garden Planner — Free

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