Blog

When to Plant Echinacea in Billings County, ND

Billings County, North Dakota Zone 4a May

Your May game plan for Billings County, North Dakota

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

Avg. last frost May 19
Avg. first frost September 21
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.9 hrs
  1. Harden off and plant echinacea

    Your last frost (May 19) has passed. These warm-season crops can handle outdoor soil now.

Instant PDF download. No spam, unsubscribe any time.

Echinacea (purple coneflower) is a native prairie perennial valued for its immune-supporting properties and beautiful daisy-like flowers that attract pollinators.

Billings County, North Dakota is in USDA Zone 4a. The average last spring frost is May 19 and the first fall frost is September 21, giving you a growing season of approximately 125 days.

At an elevation of 894 feet, Billings County receives approximately 26.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Echinacea to ensure they mature before fall.

Billings County, ND (Zone 4a) Short season
125 days
Last Spring Frost May 19
125 growing days
First Fall Frost September 21

Billings County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 21 🍅 Harvest: Sep 24 – Oct 15
Recommended (50%) ✗ May not fit
Transplant: May 26 🍅 Harvest: Sep 29 – Oct 20
Safe Start (90%) ✗ May not fit
Transplant: Jun 9 🍅 Harvest: Oct 13 – Nov 3

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 Billings County

How your county's soil matches Echinacea's growing requirements.

Soil pH

Your soil pH (6.5–7.4) overlaps with Echinacea's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Billings County is excellent for Echinacea — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Echinacea.

How to Plant Echinacea

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

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

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Echinacea

Echinacea 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 Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 2.3" 0" ✅ Rainfall sufficient
Aug 2.2" 2.9" 0" ✅ Rainfall sufficient
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2" 0" ❄️ Dormant
Nov 1.7" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Echinacea 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 needs ~1,950 GDD — county provides 1,625 GDD May not mature

Echinacea Planting Timeline — Billings County, ND

Echinacea Planting Calendar

Activity When Date Range
Transplant Outdoors May 26 May 26 – Jun 9
Harvest September 29 Sep 29 – Oct 20

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

125 days in Billings County

Growing Tips for Echinacea in Billings County

Direct sow Echinacea outdoors after May 19 in Billings County when soil has warmed and frost danger has passed.

Your 125.0-day growing season in Billings County is tight for Echinacea (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Echinacea 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 spring germination. Seeds need cold stratification. Deadhead to prolong blooming or leave seed heads for birds.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Echinacea in Billings County, ND?

Billings County is in Zone 4a with an average last frost of May 19. Plan your Echinacea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Billings County, ND?

Billings County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 19 and first fall frost is September 21.

🌱

Your Billings County Garden Planner — Free

A 24-page printable planner built for Billings County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Billings County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

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