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When to plant Coreopsis in Sutter County, CA

Sutter County's climate puts the Coreopsis spring window between February 11 and March 4. aim for a steady week of warm soil before planting.

When to Plant Coreopsis in Sutter County, CA

Sutter County, California Zone 9b June

June in Sutter County, California — your action list

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

Avg. last frost March 4
Avg. first frost November 26
Soil temp (4") 85°F
Watering Critical
Pest pressure High
Daylight 14.7 hrs
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Coreopsis (Tickseed) is a cheerful, long-blooming native perennial that produces a continuous flush of bright yellow, gold, or bi-colored daisy-like flowers from early summer well into fall. One of the most reliable cut-and-come-again bloomers in the perennial garden, it thrives in hot, dry, sunny conditions and poor soil where many competitors struggle. An invaluable nectar source for native bees and butterflies, and a butterfly host plant for several species.

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 Coreopsis during the growing season.

Perennial 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

Coreopsis Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Start indoors: Dec 13 Transplant: Jan 24 🌸 Bloom: Mar 21 – Aug 22
Recommended (50%) ✓ Fits season (71 days to spare)
Start indoors: Jan 7 Transplant: Feb 18 🌸 Bloom: Apr 15 – Sep 16
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Mar 2 Transplant: Apr 13 🌸 Bloom: Jun 8 – Nov 9

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 Coreopsis's growing requirements.

Soil pH

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

Soil Texture

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

Drainage

Drainage is adequate for Coreopsis.

Organic Matter

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

How to Plant Coreopsis

0.1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Coreopsis

5
successive plantings in your 267-day season

Sow every 6.9 weeks. Last sowing by Sep 07 to harvest before frost.

Coreopsis 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 Coreopsis

Coreopsis 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 Coreopsis 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.

Coreopsis 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.

Coreopsis needs ~1,120 GDD — county provides 4,272 GDD Excellent fit

Coreopsis Planting Timeline — Sutter County, CA

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors February 18 Feb 18 – Mar 4
Direct Sow February 11 Feb 11 – Mar 4
Bloom April 15 Apr 15 – Sep 16

Plant 0.1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

60–80 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 Coreopsis in Sutter County

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

Common pests for Coreopsis 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. Coreopsis needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 8–10 weeks before last frost or direct sow after last frost. Seeds germinate easily without stratification. Thrives in poor to average, well-drained soil — rich soil promotes foliage over flowers. Drought tolerant once established; overwatering is the most common mistake. Deadhead spent blooms to maintain continuous flowering through the season. Shear plants by one-third in midsummer for a fresh flush of late-season blooms. Year 2+ plants bloom most heavily. Divide every 2–3 years in early spring to rejuvenate crowded clumps.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Coreopsis in Sutter County, CA?

Sutter County is in Zone 9b with an average last frost of March 4. Plan your Coreopsis 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 Coreopsis in Sutter County, CA?

In Sutter County, CA, plant Coreopsis 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 Coreopsis?

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

Can Coreopsis grow in Sutter County's climate?

Yes — Coreopsis 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.