Blog

When to Plant Echinacea in Modoc County, CA

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

Modoc County, California is in USDA Zone 6a. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 2,205 feet, Modoc County receives approximately 28.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Echinacea to ensure they mature before fall.

Modoc County, CA (Zone 6a) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21

Modoc County Soil Profile

Soil Type

Loam

Soil pH

5.9-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 26 🍅 Harvest: Sep 29 – Dec 8
Recommended (50%) ✗ May not fit
Transplant: Jun 7 🍅 Harvest: Oct 11 – Dec 20
Safe Start (90%) ✓ Fits season (281 days to spare)
Transplant: Jun 26 🍅 Harvest: Oct 30 – Jan 8

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 Modoc County

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

Soil pH

Your soil pH (5.9โ€“7.4) overlaps with Echinacea's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Echinacea.

Organic Matter

Organic matter is moderate (2.1%). 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 5.6" 0" โ„๏ธ Dormant
Feb โ€” 5.8" 0" โ„๏ธ Dormant
Mar โ€” 4.1" 0" โ„๏ธ Dormant
Apr โ€” 2.1" 0" โ„๏ธ Dormant
May 2.2" 0.7" 1.5" ๐Ÿšฟ Regular watering
Jun 2.2" 0.1" 2.1" ๐Ÿšฟ Regular watering
Jul 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Aug 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Sep 2.2" 0.4" 1.8" ๐Ÿšฟ Regular watering
Oct โ€” 1.3" 0" โ„๏ธ Dormant
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 5.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Modoc 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 ~1,838 GDD — county provides 1,384 GDD May not mature

Echinacea Planting Timeline โ€” Modoc County, CA

Echinacea Planting Calendar

Activity When Date Range
Transplant Outdoors June 7 Jun 7 โ€“ Jun 21
Harvest October 11 Oct 11 โ€“ Dec 20

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 โ€”
June Transplant Outdoors
July โ€”
August โ€”
September โ€”
October Harvest
November Harvest
December Harvest

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 6a

๐Ÿ“† Growing Season

113 days in Modoc County

Growing Tips for Echinacea in Modoc County

Direct sow Echinacea outdoors after May 31 in Modoc County when soil has warmed and frost danger has passed.

Your 113.0-day growing season in Modoc 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 Modoc County, CA?

Modoc County is in Zone 6a with an average last frost of May 31. Plan your Echinacea planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Modoc County, CA?

Modoc County, California is in USDA Hardiness Zone 6a. The average last spring frost is May 31 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Modoc County gardeners in Zone 6a 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 Modoc County, CA. Local conditions may vary. Last updated: April 2026.