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When to Plant Echinacea in Clark County, WA

Echinacea (purple coneflower) is a native prairie perennial valued for its immune-supporting properties and beautiful daisy-like flowers that attract pollinators.

Clark County, Washington is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.

At an elevation of 482 feet, Clark County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Echinacea during the growing season.

Clark County, WA (Zone 8a) Moderate season
196 days
Last Spring Frost April 14
196 growing days
First Fall Frost October 27

Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 15 🍅 Harvest: Aug 19 – Nov 25
Recommended (50%) ✗ May not fit
Transplant: Apr 21 🍅 Harvest: Aug 25 – Dec 1
Safe Start (90%) ✗ May not fit
Transplant: May 16 🍅 Harvest: Sep 19 – Dec 26

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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Echinacea needs ~2,062 GDD — county provides 2,695 GDD Excellent fit

Echinacea Planting Timeline โ€” Clark County, WA

Echinacea Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 โ€“ May 5
Harvest August 25 Aug 25 โ€“ Dec 1

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June โ€”
July โ€”
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

120โ€“180 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8a

Growing Season

196 days

Growing Tips for Clark County

Start seeds indoors 8-10 weeks before last frost or direct sow in fall for spring germination. Seeds need cold stratification. Deadhead to prolong blooming or leave seed heads for birds.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Echinacea in Clark County, WA?

Clark County is in Zone 8a with an average last frost of April 14. Plan your Echinacea planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clark County, WA?

Clark County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clark County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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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 Clark County, WA. Local conditions may vary. Last updated: April 2026.