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When to Plant Echinacea (Purple Coneflower) in Sublette County, WY

Sublette County, Wyoming Zone 4b June

June to-do list for Sublette County, Wyoming

Welcome to June in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost June 22
Avg. first frost August 24
Soil temp (4") 47°F
Watering High
Pest pressure Moderate
Daylight 15.1 hrs
To set up a strong July, finish these tasks
  • Transplants going out: echinacea (purple coneflower)
  • Direct-sowing: 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.

Sublette County, Wyoming is in USDA Zone 4b. The average last spring frost is June 22 and the first fall frost is August 24, giving you a growing season of approximately 63 days.

At an elevation of 5,005 feet, Sublette County receives approximately 22.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Echinacea (Purple Coneflower) to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Sublette County, WY (Zone 4b) Very short season
63 days
Last Spring Frost June 22
63 growing days
First Fall Frost August 24

Sublette County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Echinacea (Purple Coneflower) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 8 Transplant: Jul 1 🌸 Bloom: Sep 30 – Dec 9
Recommended (50%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jul 6 🌸 Bloom: Oct 5 – Dec 14
Safe Start (90%) ✗ May not fit
Start indoors: Apr 21 Transplant: Jul 14 🌸 Bloom: Oct 13 – Dec 22

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 Sublette County

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

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Echinacea (Purple Coneflower) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Echinacea (Purple Coneflower).

How to Plant Echinacea (Purple Coneflower)

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

Echinacea (Purple Coneflower) Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 2.5" 0" ❄️ Dormant
Jun 2.2" 1.5" 0.7" 💧 Light watering
Jul 2.2" 2.2" 0" ✅ Rainfall sufficient
Aug 2.2" 2.1" 0.1" 💧 Light watering
Sep 1.7" 0" ❄️ Dormant
Oct 2" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Aug in Sublette 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 ~860 GDD — county provides 677 GDD May not mature

Echinacea (Purple Coneflower) Planting Timeline — Sublette County, WY

Echinacea (Purple Coneflower) Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 – Apr 27
Transplant Outdoors July 6 Jul 6 – Jul 20
Direct Sow July 6 Jul 6 – Jul 27
Bloom October 5 Oct 5 – Dec 14

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

Month-by-Month Timeline

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

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: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

63 days in Sublette County

Growing Tips for Echinacea (Purple Coneflower) in Sublette County

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

Your 63.0-day growing season in Sublette County is tight for Echinacea (Purple Coneflower) (70.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Sublette County receives only 23" of rain annually. Echinacea (Purple Coneflower) 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 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 Sublette County, WY?

Sublette County is in Zone 4b with an average last frost of June 22. Plan your Echinacea (Purple Coneflower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sublette County, WY?

Sublette County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is June 22 and first fall frost is August 24.

🌱

Your Sublette County Garden Planner — Free

A 22-page printable planner built for Sublette County (Zone 4b). 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 Sublette County, WY. 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.