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When to Plant Echinacea (Purple Coneflower) in Coos County, OR

Coos County, Oregon Zone 9a June

What to do in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Coos County, Oregon.

Avg. last frost March 22
Avg. first frost November 19
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.2 hrs
  1. It's harvest week for echinacea (purple coneflower)

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Before July arrives, get these ready
  • First harvests: echinacea (purple coneflower)

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Echinacea purpurea (Purple Coneflower) is a long-lived native prairie perennial and one of the most valuable pollinator plants in North American gardens. Its distinctive daisy-like blooms — swept-back lavender-pink petals surrounding a spiny orange-brown cone — attract bees, butterflies, and goldfinches from summer into fall. Drought-tolerant once established, adaptable to average soils, and impressively long-lived; mature clumps bloom reliably for decades.

Coos County, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Echinacea (Purple Coneflower) during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Coos County, OR (Zone 9a) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Echinacea (Purple Coneflower) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Jan 10 Transplant: Feb 21 🌸 Bloom: May 2 – Sep 19
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Jan 25 Transplant: Mar 8 🌸 Bloom: May 17 – Oct 4
Safe Start (90%) ✓ Fits season (41 days to spare)
Start indoors: Feb 25 Transplant: Apr 8 🌸 Bloom: Jun 17 – Nov 4

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 Coos County

How your county's soil matches Echinacea (Purple Coneflower)'s growing requirements.

Soil pH

Your soil pH (5.4–6.8) overlaps with Echinacea (Purple Coneflower)'s range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Coos County is excellent for Echinacea (Purple Coneflower) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) — Echinacea (Purple Coneflower) will thrive.

How to Plant Echinacea (Purple Coneflower)

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Echinacea (Purple Coneflower)

4
successive plantings in your 242-day season

Sow every 8 weeks. Last sowing by Aug 21 to harvest before frost.

Echinacea (Purple Coneflower) 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 Echinacea (Purple Coneflower)

Echinacea (Purple Coneflower) 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 Echinacea (Purple Coneflower) Needs Rainfall You Supplement Action
Jan 5.5" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 2.2" 4.4" 0" ✅ Rainfall sufficient
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 2.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 0.6" 1.6" 🚿 Regular watering
Aug 2.2" 0.8" 1.4" 🚿 Regular watering
Sep 2.2" 1.4" 0.8" 💧 Light watering
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 2.2" 5.9" 0" ✅ Rainfall sufficient
Dec 5.5" 0" ❄️ Dormant

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

Echinacea (Purple Coneflower) 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.

Echinacea (Purple Coneflower) needs ~1,340 GDD — county provides 4,053 GDD Excellent fit

Echinacea (Purple Coneflower) Planting Timeline — Coos County, OR

Echinacea (Purple Coneflower) Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 – Feb 8
Transplant Outdoors March 8 Mar 8 – Mar 22
Direct Sow March 8 Mar 8 – Mar 29
Bloom May 17 May 17 – Oct 4

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April
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 · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

242 days in Coos County

Growing Tips for Echinacea (Purple Coneflower) in Coos County

Direct sow Echinacea (Purple Coneflower) outdoors after March 22 in Coos County when soil has warmed and frost danger has passed.

Common pests for Echinacea (Purple Coneflower) in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8–10 weeks before last frost or direct-sow in fall for natural cold stratification. Seeds require 4–8 weeks of cold moist stratification (or fall sowing) for best germination. Transplant when night temps stay above 50°F. Full sun is essential for heavy bloom. Avoid over-fertilizing — lean soil produces more compact, floriferous plants. Deadhead for continuous bloom but leave some cones standing in fall for goldfinch seed harvest. Year 2+ plants bloom most heavily; first-year transplants may produce limited flowers. Divide congested clumps every 3–4 years in early spring.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Echinacea (Purple Coneflower) in Coos County, OR?

Coos County is in Zone 9a with an average last frost of March 22. Plan your Echinacea (Purple Coneflower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is March 22 and first fall frost is November 19.

🌱

Your Coos County Garden Planner — Free

A 22-page printable planner built for Coos 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 Coos 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.