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When to plant Echinacea (Purple Coneflower) in Randolph County County,

In Zone 6a (Randolph County County), direct-sow Echinacea (Purple Coneflower) between April 29 and May 20 for spring, after the April 15 last-frost mark.

When to Plant Echinacea (Purple Coneflower) in Randolph County, MO

Randolph County, Missouri Zone 6a June

This month in Randolph County, Missouri

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 15
Avg. first frost October 18
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Start echinacea (purple coneflower) under lights

    These need a head start before your last frost (April 15). Sow into cells now so you're ready to transplant in a few weeks.

July prep starts now
  • 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.

Randolph County, Missouri is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.

At an elevation of 1,243 feet, Randolph County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Echinacea (Purple Coneflower) during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Randolph County, MO (Zone 6a) Moderate season
186 days
Last Spring Frost April 15
186 growing days
First Fall Frost October 18
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Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.9

Drainage

Well Drained

Echinacea (Purple Coneflower) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 6 Transplant: Apr 24 🌸 Bloom: Jul 17 – Oct 23
Recommended (50%) ✗ May not fit
Start indoors: Feb 11 Transplant: Apr 29 🌸 Bloom: Jul 22 – Oct 28
Safe Start (90%) ✗ May not fit
Start indoors: Feb 25 Transplant: May 13 🌸 Bloom: Aug 5 – Nov 11

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 Randolph County

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

Soil pH

Your soil pH (5.7–6.9) overlaps with Echinacea (Purple Coneflower)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Echinacea (Purple Coneflower).

How to Plant Echinacea (Purple Coneflower)

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

Succession Planting Echinacea (Purple Coneflower)

3
successive plantings in your 186-day season

Sow every 8 weeks. Last sowing by Jul 20 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
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 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.1" 0" ✅ Rainfall sufficient
Sep 2.2" 2.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Randolph 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 ~1,100 GDD — county provides 2,557 GDD Excellent fit

Echinacea (Purple Coneflower) Planting Timeline — Randolph County, MO

Echinacea (Purple Coneflower) Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 29 Apr 29 – May 20
Bloom July 22 Jul 22 – Oct 28

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Bloom
August Bloom
September Bloom
October Bloom
November
December
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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 6a

📆 Growing Season

186 days in Randolph County

Growing Tips for Echinacea (Purple Coneflower) in Randolph County

Direct sow Echinacea (Purple Coneflower) outdoors after April 15 in Randolph 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 Randolph County, MO?

Randolph County is in Zone 6a with an average last frost of April 15. Plan your Echinacea (Purple Coneflower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, MO?

Randolph County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 18.

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

In Randolph County, , plant Echinacea (Purple Coneflower) after the last frost (around April 15) and before the first frost (around October 18). Best results when soil holds above 50°F.

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

Randolph County sits in USDA Zone 6a. Echinacea (Purple Coneflower) grows reliably in zones 3a through 9b, so it's a good fit here.

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

Yes — Echinacea (Purple Coneflower) grows well in Randolph County's temperate climate. Randolph County averages a 186-day frost-free season, with last frost around April 15 and first frost around October 18.

🌱

Your Randolph County Garden Planner — Free

A 22-page printable planner built for Randolph County (Zone 6a). 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 Randolph County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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