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When to plant Echinacea (Purple Coneflower) in Monroe County, IA

Monroe County sits in USDA Zone 5b. Plant Echinacea (Purple Coneflower) between May 10 (after last frost on April 26) and May 31.

When to Plant Echinacea (Purple Coneflower) in Monroe County, IA

Monroe County, Iowa Zone 5b June

What to do in June

Your Monroe County, Iowa garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 26
Avg. first frost October 13
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Start echinacea (purple coneflower) indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

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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.

Monroe County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 13, giving you a growing season of approximately 170 days.

At an elevation of 968 feet, Monroe County receives approximately 32.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Echinacea (Purple Coneflower) during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Monroe County, IA (Zone 5b) Moderate season
170 days
Last Spring Frost April 26
170 growing days
First Fall Frost October 13

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Echinacea (Purple Coneflower) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 14 Transplant: May 2 🌸 Bloom: Jul 25 – Oct 24
Recommended (50%) ✗ May not fit
Start indoors: Feb 22 Transplant: May 10 🌸 Bloom: Aug 2 – Nov 1
Safe Start (90%) ✗ May not fit
Start indoors: Mar 11 Transplant: May 27 🌸 Bloom: Aug 19 – Nov 18

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 Monroe County

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

Soil pH

Your soil pH (6.2–7.3) overlaps with Echinacea (Purple Coneflower)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — 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)

2
successive plantings in your 170-day season

Sow every 8 weeks. Last sowing by Jul 15 to harvest before frost.

Echinacea (Purple Coneflower) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 2.8" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.3" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.3" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.3" 0" ✅ Rainfall sufficient
Nov 2.1" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Monroe 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 ~1,220 GDD — county provides 2,592 GDD Excellent fit

Echinacea (Purple Coneflower) Planting Timeline — Monroe County, IA

Echinacea (Purple Coneflower) Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 10 May 10 – May 31
Bloom August 2 Aug 2 – Nov 1

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors Direct Sow
June
July
August Bloom
September Bloom
October Bloom
November Bloom
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 5b

📆 Growing Season

170 days in Monroe County

Growing Tips for Echinacea (Purple Coneflower) in Monroe County

Direct sow Echinacea (Purple Coneflower) outdoors after April 26 in Monroe 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 Monroe County, IA?

Monroe County is in Zone 5b with an average last frost of April 26. Plan your Echinacea (Purple Coneflower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, IA?

Monroe County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 13.

When should I plant Echinacea (Purple Coneflower) in Monroe County, IA?

In Monroe County, IA, plant Echinacea (Purple Coneflower) after the last frost (around April 26) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Monroe County, IA for Echinacea (Purple Coneflower)?

Monroe County sits in USDA Zone 5b. Echinacea (Purple Coneflower) grows reliably in zones 3a through 9b, so it's a good fit here.

Can Echinacea (Purple Coneflower) grow in Monroe County's climate?

Yes — Echinacea (Purple Coneflower) grows well in Monroe County's temperate climate. Monroe County averages a 170-day frost-free season, with last frost around April 26 and first frost around October 13.

🌱

Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe County (Zone 5b). 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 Monroe County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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