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When to plant Yarrow in Pullman,

In Zone 6a (Pullman), direct-sow Yarrow between May 2 and May 23 for spring, after the May 2 last-frost mark.

When to Plant Yarrow in Pullman, MI

Pullman, MI Zone 6a June

June in the garden — Pullman, MI

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Pullman, MI.

Avg. last frost May 2
Avg. first frost October 14
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
Coming up in July — start thinking about
  • 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.

Pullman, Michigan is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 14, giving you a growing season of approximately 165 days.

At an elevation of 1,257 feet, Allegan County receives approximately 37.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Yarrow during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Pullman, MI (Zone 6a) Moderate season
165 days
Last Spring Frost May 2
165 growing days
First Fall Frost October 14

Pullman Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.7

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 23 Transplant: May 4 🌸 Bloom: Jul 13 – Nov 2
Recommended (50%) ✗ May not fit
Start indoors: Feb 28 Transplant: May 9 🌸 Bloom: Jul 18 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: Mar 19 Transplant: May 28 🌸 Bloom: Aug 6 – Nov 26

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 Pullman

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

Soil pH

Your soil pH (6.2–6.7) is within Yarrow's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Yarrow will thrive.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

3
successive plantings in your 165-day season

Sow every 6.9 weeks. Last sowing by Jul 16 to harvest before frost.

Yarrow Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 1.6" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.2" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Allegan 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 ~1,088 GDD — county provides 2,392 GDD Excellent fit

Yarrow Planting Timeline — Pullman, MI

Yarrow Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 2 May 2 – May 23
Bloom July 18 Jul 18 – Nov 7

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
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: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

165 days in Allegan County

Growing Tips for Yarrow in Pullman

Direct sow Yarrow outdoors after May 02 in Allegan 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.

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 →

When should I plant Yarrow in Pullman, ?

In Pullman, , plant Yarrow after the last frost (around May 2) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Pullman, for Yarrow?

Pullman sits in USDA Zone 6a. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Pullman's climate?

Yes — Yarrow grows well in Pullman's temperate climate. Pullman averages a 165-day frost-free season, with last frost around May 2 and first frost around October 14.

🌱

Your Allegan County Garden Planner — Free

A 22-page printable planner built for Allegan County (Zone 6a). 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 Allegan County, MI. Local conditions may vary. Last updated: June 2026.