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When to plant Zinnia in Sutter County, CA

In Zone 9b (Sutter County), direct-sow Zinnia between February 4 and February 25 for spring, after the March 4 last-frost mark.

When to Plant Zinnia in Sutter County, CA

Sutter County, California Zone 9b June

Top priorities for Sutter County, California gardeners in June

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

Avg. last frost March 4
Avg. first frost November 26
Soil temp (4") 85°F
Watering Critical
Pest pressure High
Daylight 14.7 hrs
  1. Collect zinnia at their peak

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

July prep starts now
  • First harvests: zinnia

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Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Sutter County, California is in USDA Zone 9b. The average last spring frost is March 4 and the first fall frost is November 26, giving you a growing season of approximately 267 days.

At an elevation of 484 feet, Sutter County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Zinnia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Sutter County, CA (Zone 9b) Long season
267 days
Last Spring Frost March 4
267 growing days
First Fall Frost November 26

Sutter County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Start indoors: Jan 10 Transplant: Jan 10 🌸 Bloom: Mar 21 – Sep 19
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Feb 4 Transplant: Feb 4 🌸 Bloom: Apr 15 – Oct 14
Safe Start (90%) ✓ Fits season (10 days to spare)
Start indoors: Mar 30 Transplant: Mar 30 🌸 Bloom: Jun 8 – Dec 7

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 Sutter County

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

Soil pH

Your soil pH (6.8–7.7) overlaps with Zinnia's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Zinnia.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Zinnia.

How to Plant Zinnia

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Zinnia

5
successive plantings in your 267-day season

Sow every 6.9 weeks. Last sowing by Sep 17 to harvest before frost.

Zinnia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 894 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Zinnia

Zinnia needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Zinnia Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 2.2" 3.7" 0" ✅ Rainfall sufficient
Apr 2.2" 1.4" 0.8" 💧 Light watering
May 2.2" 0.6" 1.6" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.2" 2" 🚿 Regular watering
Oct 2.2" 0.9" 1.3" 🚿 Regular watering
Nov 2.2" 1.8" 0.4" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

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

Zinnia 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.

Zinnia needs ~1,040 GDD — county provides 4,272 GDD Excellent fit

Zinnia Planting Timeline — Sutter County, CA

Zinnia Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow February 4 Feb 4 – Feb 25
Bloom April 15 Apr 15 – Oct 14

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

267 days in Sutter County

Growing Tips for Zinnia in Sutter County

Direct sow Zinnia outdoors after March 04 in Sutter County when soil has warmed and frost danger has passed.

Common pests for Zinnia in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Sutter County receives only 21" of rain annually. Zinnia needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct-sow after last frost when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Sutter County, CA?

Sutter County is in Zone 9b with an average last frost of March 4. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sutter County, CA?

Sutter County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 4 and first fall frost is November 26.

When should I plant Zinnia in Sutter County, CA?

In Sutter County, CA, plant Zinnia after the last frost (around March 4) and before the first frost (around November 26). Best results when soil holds above 50°F.

What growing zone is Sutter County, CA for Zinnia?

Sutter County sits in USDA Zone 9b. Zinnia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zinnia grow in Sutter County's climate?

Yes — Zinnia grows well in Sutter County's temperate climate. Sutter County averages a 267-day frost-free season, with last frost around March 4 and first frost around November 26.

🌱

Your Sutter County Garden Planner — Free

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.