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When to plant Yarrow in Comptche, CA

The best window to plant Yarrow in Comptche, is March 2–March 23, when soil warms to 50°F. Last frost typically hits March 23; first frost November 9.

When to Plant Yarrow in Comptche, CA

Mendocino County, California Zone 9b June

What to do in June

Each item below is timed to Mendocino County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 23
Avg. first frost November 9
Soil temp (4") 84°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs
  1. Harvest yarrow as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

July will be here before you know it — start on
  • First harvests: yarrow

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Achillea millefolium (Yarrow) is a tough, drought-tolerant native perennial with aromatic finely-divided foliage and broad flat-topped flower clusters that serve as a landing platform for hundreds of beneficial insect species. Available in white (the species type) and a wide range of cultivars spanning yellow, gold, pink, salmon, and deep red. Spreads by rhizome to form ground-covering colonies; blooms from late spring through midsummer with reblooming into fall if deadheaded. Exceptional in hot, dry sites where other perennials fail.

Comptche, California is in USDA Zone 9b. The average last spring frost is March 23 and the first fall frost is November 9, giving you a growing season of approximately 231 days.

At an elevation of 180 feet, Mendocino County receives approximately 24 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Yarrow during the growing season. Sandy soil warms quickly in spring — great for early planting — but Yarrow will need more frequent watering and organic matter to retain nutrients.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Comptche, CA (Zone 9b) Long season
231 days
Last Spring Frost March 23
231 growing days
First Fall Frost November 9

Comptche Soil Profile

Soil Type

Sandy Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Monthly Watering Guide for Yarrow

Yarrow needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Yarrow Needs Rainfall You Supplement Action
Jan 5.2" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 1.9" 2.4" 🚿 Regular watering
May 4.3" 0.6" 3.7" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 1" 3.3" 🚿 Regular watering
Nov 4.3" 2.6" 1.7" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

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

Yarrow Planting Timeline — Comptche, CA

Yarrow Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 – Feb 9
Transplant Outdoors March 9 Mar 9 – Mar 23
Direct Sow March 2 Mar 2 – Mar 23
Bloom May 4 May 4 – Sep 7

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

231 days in Mendocino County

Growing Tips for Comptche

Start seeds indoors 8–10 weeks before last frost; seeds need light for germination — press onto soil surface, do not cover. Direct sow after last frost or divide established clumps in spring or fall. Thrives in poor, well-drained soil — rich soil and high fertility cause floppy stems and reduce flower count. Avoid overwatering; excellent drought tolerance once established. Deadhead spent clusters to encourage rebloom. Divide every 2–3 years to prevent center die-out and control spread. Year 2+ plants bloom most heavily; first-year plants may produce limited flowers. Dried flowers retain color well for arrangements.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

When should I plant Yarrow in Comptche, CA?

In Comptche, CA, plant Yarrow after the last frost (around March 23) and before the first frost (around November 9). Best results when soil holds above 50°F.

What growing zone is Comptche, CA for Yarrow?

Comptche sits in USDA Zone 9b. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Comptche's climate?

Yes — Yarrow grows well in Comptche's temperate climate. Comptche averages a 231-day frost-free season, with last frost around March 23 and first frost around November 9.

🌱

Your Mendocino County Garden Planner — Free

A 22-page printable planner built for Mendocino County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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