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When to plant Yarrow in Trinity County County,

Aim to plant Yarrow in Trinity County County on or after April 5; the window stays open through April 26. Trinity County County's 189-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Yarrow in Trinity County, CA

Trinity County, California Zone 8b June

June to-do list for Trinity County, California

We've pulled the most time-sensitive tasks for Trinity County, California this June and put them front and centre. Tackle them in order.

Avg. last frost April 19
Avg. first frost October 25
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
  1. Time to start yarrow inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Pick yarrow

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of July
  • 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.

Trinity County, California is in USDA Zone 8b. The average last spring frost is April 19 and the first fall frost is October 25, giving you a growing season of approximately 189 days.

At an elevation of 61 feet, Trinity County receives approximately 30.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 79°F, so choose short-season varieties of Yarrow to ensure they mature before fall. 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
Trinity County, CA (Zone 8b) Moderate season
189 days
Last Spring Frost April 19
189 growing days
First Fall Frost October 25

Trinity County Soil Profile

Soil Type

Sandy Loam

Soil pH

6-7.1

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 6.2" 0" ❄️ Dormant
Feb 6.6" 0" ❄️ Dormant
Mar 5" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 0.9" 3.4" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 2.9" 0" ❄️ Dormant
Dec 4.9" 0" ❄️ Dormant

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

Yarrow Planting Timeline — Trinity County, CA

Yarrow Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 5 Apr 5 – Apr 26
Bloom June 21 Jun 21 – Nov 15

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
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 8b

📆 Growing Season

189 days in Trinity County

Growing Tips for Trinity County

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 →

Frequently Asked Questions

When should I plant Yarrow in Trinity County, CA?

Trinity County is in Zone 8b with an average last frost of April 19. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Trinity County, CA?

Trinity County, California is in USDA Hardiness Zone 8b. The average last spring frost is April 19 and first fall frost is October 25.

When should I plant Yarrow in Trinity County County, ?

In Trinity County County, , plant Yarrow after the last frost (around April 19) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Trinity County County, for Yarrow?

Trinity County County sits in USDA Zone 8b. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Trinity County County's climate?

Yes — Yarrow grows well in Trinity County County's temperate climate. Trinity County County averages a 189-day frost-free season, with last frost around April 19 and first frost around October 25.

🌱

Your Trinity County Garden Planner — Free

A 22-page printable planner built for Trinity County (Zone 8b). 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 Trinity County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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