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When to Plant Yarrow in Lake County, CA

Yarrow is a drought-tolerant perennial herb with feathery foliage and flat-topped flower clusters in white, yellow, pink, or red. It attracts beneficial insects and is used in herbal medicine.

Lake County, California is in USDA Zone 8b. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.

At an elevation of 154 feet, Lake County receives approximately 30.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Yarrow to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Yarrow will need more frequent watering and organic matter to retain nutrients.

Lake County, CA (Zone 8b) Year-round
270 days
Last Spring Frost March 2
270 growing days
First Fall Frost November 27

Lake County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (103 days to spare)
Transplant: Feb 21 🍅 Harvest: May 23 – Aug 8
Recommended (50%) ✓ Fits season (95 days to spare)
Transplant: Mar 9 🍅 Harvest: Jun 8 – Aug 24
Safe Start (90%) ✓ Fits season (66 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 24 – Oct 9

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 Lake County

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

Soil pH

Your soil pH (6.1โ€“6.9) is within Yarrow's preferred range (5.5โ€“7.0).

Soil Texture

Sandy soil in Lake County warms quickly in spring but drains fast. Yarrow will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Yarrow.

How to Plant Yarrow

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 65 gal / 100 sq ft

Monthly Watering Guide for Yarrow

Yarrow 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 Yarrow Needs Rainfall You Supplement Action
Jan โ€” 6.2" 0" โ„๏ธ Dormant
Feb โ€” 6.5" 0" โ„๏ธ Dormant
Mar 2.2" 4.6" 0" โœ… Rainfall sufficient
Apr 2.2" 2.7" 0" โœ… Rainfall sufficient
May 2.2" 0.8" 1.4" ๐Ÿšฟ Regular watering
Jun 2.2" 0.2" 2" ๐Ÿšฟ Regular watering
Jul 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Aug 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Sep 2.2" 0.3" 1.9" ๐Ÿšฟ Regular watering
Oct 2.2" 1.1" 1.1" ๐Ÿšฟ Regular watering
Nov 2.2" 3" 0" โœ… Rainfall sufficient
Dec โ€” 5.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Lake County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Yarrow 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.

Yarrow needs ~1,286 GDD — county provides 3,307 GDD Excellent fit

Yarrow Planting Timeline โ€” Lake County, CA

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors March 9 Mar 9 โ€“ Mar 23
Harvest June 8 Jun 8 โ€“ Aug 24

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

Month-by-Month Timeline

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

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

90โ€“120 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

270 days in Lake County

Growing Tips for Yarrow in Lake County

Direct sow Yarrow outdoors after March 02 in Lake County when soil has warmed and frost danger has passed.

Sandy soil in Lake County dries quickly โ€” mulch Yarrow with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

General growing tips

Direct sow or start from divisions. Yarrow thrives in poor soil and is very drought-tolerant. Deadhead to encourage reblooming. Divide clumps every 3 years.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Yarrow in Lake County, CA?

Lake County is in Zone 8b with an average last frost of March 2. Plan your Yarrow planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lake County, CA?

Lake County, California is in USDA Hardiness Zone 8b. The average last spring frost is March 2 and first fall frost is November 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lake County gardeners in Zone 8b 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 Lake County, CA. Local conditions may vary. Last updated: April 2026.