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When to Plant Coreopsis in Lake County, OR

Lake County, Oregon Zone 6b June

This month in Lake County, Oregon

Welcome to June in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost June 16
Avg. first frost September 7
Soil temp (4") 68°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. Move coreopsis from tray to bed

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Scatter coreopsis into prepared beds

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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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.

Lake County, Oregon is in USDA Zone 6b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 1,236 feet, Lake County receives approximately 12.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Coreopsis during the growing season. With low rainfall, drip irrigation is essential for growing Coreopsis successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Lake County, OR (Zone 6b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.4

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 9 🌸 Bloom: Aug 18 – Dec 15
Recommended (50%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 23 🌸 Bloom: Sep 1 – Dec 29
Safe Start (90%) ✓ Fits season (265 days to spare)
Start indoors: Apr 24 Transplant: Jul 3 🌸 Bloom: Sep 11 – Jan 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 Lake County

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

Soil pH

Your soil pH (5.7–6.4) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) — Coreopsis will thrive.

How to Plant Coreopsis

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

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 0.8" 0" ❄️ Dormant
May 0.7" 0" ❄️ Dormant
Jun 2.2" 0.5" 1.7" 🚿 Regular watering
Jul 2.2" 0.2" 2" 🚿 Regular watering
Aug 2.2" 0.2" 2" 🚿 Regular watering
Sep 2.2" 0.5" 1.7" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 1.9" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Lake 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 1,328 GDD Good fit

Coreopsis Planting Timeline — Lake County, OR

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors June 23 Jun 23 – Jul 7
Direct Sow June 16 Jun 16 – Jul 7
Bloom September 1 Sep 1 – Dec 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

83 days in Lake County

Growing Tips for Coreopsis in Lake County

Direct sow Coreopsis outdoors after June 16 in Lake County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Lake County is tight for Coreopsis (60.0-80.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Lake County receives only 13" 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 Lake County, OR?

Lake County is in Zone 6b with an average last frost of June 16. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, OR?

Lake County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 16 and first fall frost is September 7.

🌱

Your Lake County Garden Planner — Free

A 22-page printable planner built for Lake County (Zone 6b). 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 Lake County, OR. 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.