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When to plant Yarrow in Camas County, ID

Aim to plant Yarrow in Camas County on or after May 3; the window stays open through May 24. Camas County's 153-day frost-free season gives you a single solid spring crop with a brief fall option.

When to Plant Yarrow in Camas County, ID

Camas County, Idaho Zone 5a June

Your June planting checklist for Camas County, Idaho

June is a pivotal month for Camas County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 3
Avg. first frost October 3
Soil temp (4") 52°F
Watering High
Pest pressure High
Daylight 15.2 hrs
July will be here before you know it — start on
  • Starting indoors: yarrow
  • 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.

Camas County, Idaho is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 3, giving you a growing season of approximately 153 days.

At an elevation of 5,406 feet, Camas County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Yarrow during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Camas County, ID (Zone 5a) Moderate season
153 days
Last Spring Frost May 3
153 growing days
First Fall Frost October 3

Camas County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.2

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 25 Transplant: May 13 🌸 Bloom: Jul 22 – Oct 28
Recommended (50%) ✗ May not fit
Start indoors: Mar 1 Transplant: May 17 🌸 Bloom: Jul 26 – Nov 1
Safe Start (90%) ✗ May not fit
Start indoors: Mar 30 Transplant: Jun 15 🌸 Bloom: Aug 24 – Nov 30

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 Camas County

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

Soil pH

Your soil pH (6.4–8.2) is more alkaline than Yarrow prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Camas County is excellent for Yarrow — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Yarrow.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

2
successive plantings in your 153-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

Yarrow Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.5" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 2.2" 2.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 2" 0.2" 💧 Light watering
Aug 2.2" 2.4" 0" ✅ Rainfall sufficient
Sep 2.2" 1.6" 0.6" 💧 Light watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Camas County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,144 GDD — county provides 2,333 GDD Excellent fit

Yarrow Planting Timeline — Camas County, ID

Yarrow Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 3 May 3 – May 24
Bloom July 26 Jul 26 – Nov 1

· 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

153 days in Camas County

Growing Tips for Yarrow in Camas County

Direct sow Yarrow outdoors after May 03 in Camas County when soil has warmed and frost danger has passed.

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

Camas County receives only 21" of rain annually. Yarrow needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Camas County, ID?

Camas County is in Zone 5a with an average last frost of May 3. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Camas County, ID?

Camas County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 3.

When should I plant Yarrow in Camas County, ID?

In Camas County, ID, plant Yarrow after the last frost (around May 3) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Camas County, ID for Yarrow?

Camas County sits in USDA Zone 5a. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Camas County's climate?

Yes — Yarrow grows well in Camas County's temperate climate. Camas County averages a 153-day frost-free season, with last frost around May 3 and first frost around October 3.

🌱

Your Camas County Garden Planner — Free

A 22-page printable planner built for Camas County (Zone 5a). 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 Camas County, ID. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.