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When to Plant Echinacea (Purple Coneflower) in Union County, NM

Union County, New Mexico Zone 6b August

August in Union County, New Mexico — your action list

August rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Union County, New Mexico.

Avg. last frost April 30
Avg. first frost October 9
Soil temp (4") 62°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Harvest echinacea (purple coneflower) as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

September will be here before you know it — start on
  • 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.

Union County, New Mexico is in USDA Zone 6b. The average last spring frost is April 30 and the first fall frost is October 9, giving you a growing season of approximately 162 days.

At an elevation of 6,384 feet, Union County receives approximately 17.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 85°F, providing good warmth for Echinacea (Purple Coneflower) during the growing season. Sandy soil warms quickly in spring — great for early planting — but Echinacea (Purple Coneflower) will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Echinacea (Purple Coneflower) successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Union County, NM (Zone 6b) Moderate season
162 days
Last Spring Frost April 30
162 growing days
First Fall Frost October 9

Union County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.3

Drainage

Well Drained

Echinacea (Purple Coneflower) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 21 Transplant: May 2 🌸 Bloom: Jul 18 – Nov 7
Recommended (50%) ✗ May not fit
Start indoors: Feb 26 Transplant: May 7 🌸 Bloom: Jul 23 – Nov 12
Safe Start (90%) ✗ May not fit
Start indoors: Mar 15 Transplant: May 24 🌸 Bloom: Aug 9 – Nov 29

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 Union County

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

Soil pH

Your soil pH (6.9–8.3) is more alkaline than Echinacea (Purple Coneflower) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Union County warms quickly in spring but drains fast. Echinacea (Purple Coneflower) will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Echinacea (Purple Coneflower).

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Echinacea (Purple Coneflower).

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 162-day season

Sow every 8 weeks. Last sowing by Jul 11 to harvest before frost.

Echinacea (Purple Coneflower) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 340 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 1.1" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 2.2" 0.6" 1.6" 🚿 Regular watering
May 2.2" 0.4" 1.8" 🚿 Regular watering
Jun 2.2" 0.6" 1.6" 🚿 Regular watering
Jul 2.2" 3" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Union 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 2,227 GDD Excellent fit

Echinacea (Purple Coneflower) Planting Timeline — Union County, NM

Echinacea (Purple Coneflower) Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 7 May 7 – May 21
Direct Sow May 7 May 7 – May 28
Bloom July 23 Jul 23 – Nov 12

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 Bloom
August Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

162 days in Union County

Growing Tips for Echinacea (Purple Coneflower) in Union County

Direct sow Echinacea (Purple Coneflower) outdoors after April 30 in Union County when soil has warmed and frost danger has passed.

Sandy soil in Union County dries quickly — mulch Echinacea (Purple Coneflower) with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

Union County receives only 18" 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 Union County, NM?

Union County is in Zone 6b with an average last frost of April 30. Plan your Echinacea (Purple Coneflower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, NM?

Union County, New Mexico is in USDA Hardiness Zone 6b. The average last spring frost is April 30 and first fall frost is October 9.

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A 22-page printable planner built for Union County (Zone 6b). 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 Union County, NM. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.