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When to Plant Echinacea in Trempealeau County, WI

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

Trempealeau County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 30, giving you a growing season of approximately 138 days.

At an elevation of 1,222 feet, Trempealeau County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Echinacea to ensure they mature before fall.

Trempealeau County, WI (Zone 4b) Short season
138 days
Last Spring Frost May 15
138 growing days
First Fall Frost September 30

Trempealeau County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 16 🍅 Harvest: Sep 19 – Oct 10
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Sep 25 – Oct 16
Safe Start (90%) ✗ May not fit
Transplant: May 29 🍅 Harvest: Oct 2 – Oct 23

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 Trempealeau County

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

Soil pH

Your soil pH (5.7โ€“7.2) overlaps with Echinacea's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Trempealeau County is excellent for Echinacea โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) โ€” Echinacea will thrive.

How to Plant Echinacea

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

Plant Water Budget

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

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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 4.1" 0" โ„๏ธ Dormant
May 2.2" 4.4" 0" โœ… Rainfall sufficient
Jun 2.2" 4.9" 0" โœ… Rainfall sufficient
Jul 2.2" 4.2" 0" โœ… Rainfall sufficient
Aug 2.2" 4.1" 0" โœ… Rainfall sufficient
Sep 2.2" 3.5" 0" โœ… Rainfall sufficient
Oct โ€” 3.6" 0" โ„๏ธ Dormant
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Trempealeau County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,612 GDD — county provides 1,483 GDD Tight fit

Echinacea Planting Timeline โ€” Trempealeau County, WI

Echinacea Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 โ€“ Jun 5
Harvest September 25 Sep 25 โ€“ Oct 16

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

138 days in Trempealeau County

Growing Tips for Echinacea in Trempealeau County

Direct sow Echinacea outdoors after May 15 in Trempealeau County when soil has warmed and frost danger has passed.

Your 138.0-day growing season in Trempealeau 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 Trempealeau County, WI?

Trempealeau County is in Zone 4b with an average last frost of May 15. Plan your Echinacea planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Trempealeau County, WI?

Trempealeau County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Trempealeau County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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