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When to Plant Yarrow in Deschutes County, OR

Deschutes County, Oregon Zone 6b July

July in the garden — Deschutes County, Oregon

Here's what deserves your attention in Deschutes County, Oregon this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost June 15
Avg. first frost September 13
Soil temp (4") 82°F
Watering Critical
Pest pressure High
Daylight 15 hrs
Before August arrives, get these ready
  • 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.

Deschutes County, Oregon is in USDA Zone 6b. The average last spring frost is June 15 and the first fall frost is September 13, giving you a growing season of approximately 90 days.

At an elevation of 221 feet, Deschutes County receives approximately 54.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Yarrow to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yarrow root diseases.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Deschutes County, OR (Zone 6b) Very short season
90 days
Last Spring Frost June 15
90 growing days
First Fall Frost September 13

Deschutes County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: Jun 10 🌸 Bloom: Aug 19 – Dec 16
Recommended (50%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jun 22 🌸 Bloom: Aug 31 – Dec 28
Safe Start (90%) ✓ Fits season (271 days to spare)
Start indoors: Apr 24 Transplant: Jul 3 🌸 Bloom: Sep 11 – Jan 8

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 Deschutes County

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

Soil pH

Your soil pH (5.4–6.2) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Yarrow will thrive.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Yarrow Water Budget

Plant needs
0.5″/week
Rainfall provides
2.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 7.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 3" 0" ❄️ Dormant
Jun 2.2" 2.5" 0" ✅ Rainfall sufficient
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1" 1.2" 🚿 Regular watering
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 4.9" 0" ❄️ Dormant
Nov 7.8" 0" ❄️ Dormant
Dec 9.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Deschutes 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 ~806 GDD — county provides 967 GDD Good fit

Yarrow Planting Timeline — Deschutes County, OR

Yarrow Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 – Apr 27
Transplant Outdoors June 22 Jun 22 – Jul 6
Direct Sow June 15 Jun 15 – Jul 6
Bloom August 31 Aug 31 – Dec 28

· 18" apart · Rows 24" apart

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

90 days in Deschutes County

Growing Tips for Yarrow in Deschutes County

Direct sow Yarrow outdoors after June 15 in Deschutes County when soil has warmed and frost danger has passed.

Your 90.0-day growing season in Deschutes County is tight for Yarrow (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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

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 Deschutes County, OR?

Deschutes County is in Zone 6b with an average last frost of June 15. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Deschutes County, OR?

Deschutes County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 15 and first fall frost is September 13.

🌱

Your Deschutes County Garden Planner — Free

A 22-page printable planner built for Deschutes County (Zone 6b). 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 Deschutes County, OR. Local conditions may vary. Last updated: July 2026.

Sources & credits

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