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When to Plant Echinacea in Mariposa County, CA

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

Mariposa County, California is in USDA Zone 7b. The average last spring frost is April 18 and the first fall frost is November 9, giving you a growing season of approximately 205 days.

At an elevation of 192 feet, Mariposa County receives approximately 19.2 inches of rainfall annually with predominantly loam soil. Summer highs average 91ยฐF, providing good warmth for Echinacea during the growing season. With low rainfall, drip irrigation is essential for growing Echinacea successfully. Mulch heavily to conserve soil moisture.

Mariposa County, CA (Zone 7b) Long season
205 days
Last Spring Frost April 18
205 growing days
First Fall Frost November 9

Mariposa County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 31 🍅 Harvest: Aug 4 – Nov 10
Recommended (50%) ✗ May not fit
Transplant: Apr 25 🍅 Harvest: Aug 29 – Dec 5
Safe Start (90%) ✓ Fits season (333 days to spare)
Transplant: May 25 🍅 Harvest: Sep 28 – Jan 4

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 Mariposa County

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

Soil pH

Your soil pH (6.5โ€“7.5) overlaps with Echinacea's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 233 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€” 3.7" 0" โ„๏ธ Dormant
Feb โ€” 4.3" 0" โ„๏ธ Dormant
Mar โ€” 3.2" 0" โ„๏ธ Dormant
Apr 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
May 2.2" 0.5" 1.7" 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" 0.2" 2" ๐Ÿšฟ Regular watering
Oct 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Nov 2.2" 1.9" 0.3" ๐Ÿ’ง Light watering
Dec โ€” 2.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Mariposa 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 ~2,738 GDD — county provides 3,741 GDD Excellent fit

Echinacea Planting Timeline โ€” Mariposa County, CA

Echinacea Planting Calendar

Activity When Date Range
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Harvest August 29 Aug 29 โ€“ Dec 5

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

205 days in Mariposa County

Growing Tips for Echinacea in Mariposa County

Direct sow Echinacea outdoors after April 18 in Mariposa County when soil has warmed and frost danger has passed.

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

Mariposa County receives only 19" of rain annually. Echinacea needs consistent moisture โ€” 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 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 Mariposa County, CA?

Mariposa County is in Zone 7b with an average last frost of April 18. Plan your Echinacea planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mariposa County, CA?

Mariposa County, California is in USDA Hardiness Zone 7b. The average last spring frost is April 18 and first fall frost is November 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mariposa County gardeners in Zone 7b 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 Mariposa County, CA. Local conditions may vary. Last updated: April 2026.