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When to plant Yarrow in Mason County, MI

Mason County's short 145-day growing season means one Yarrow planting between May 15 and June 5. No fall crop in Zone 6a.

When to Plant Yarrow in Mason County, MI

Mason County, Michigan Zone 6a June

Your June planting checklist for Mason County, Michigan

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

Avg. last frost May 15
Avg. first frost October 7
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15.3 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.

Mason County, Michigan is in USDA Zone 6a. The average last spring frost is May 15 and the first fall frost is October 7, giving you a growing season of approximately 145 days.

At an elevation of 1,318 feet, Mason County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Yarrow during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Mason County, MI (Zone 6a) Short season
145 days
Last Spring Frost May 15
145 growing days
First Fall Frost October 7

Mason County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 6 Transplant: May 15 🌸 Bloom: Jul 24 – Nov 13
Recommended (50%) ✗ May not fit
Start indoors: Mar 13 Transplant: May 22 🌸 Bloom: Jul 31 – Nov 20
Safe Start (90%) ✗ May not fit
Start indoors: Mar 27 Transplant: Jun 5 🌸 Bloom: Aug 14 – Dec 4

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 Mason County

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

Soil pH

Your soil pH (6.0–7.3) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — Yarrow will thrive.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

2
successive plantings in your 145-day season

Sow every 6.9 weeks. Last sowing by Jul 09 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 1.3" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.1" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Mason 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 ~1,031 GDD — county provides 1,993 GDD Excellent fit

Yarrow Planting Timeline — Mason County, MI

Yarrow Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 15 May 15 – Jun 5
Bloom July 31 Jul 31 – Nov 20

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
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: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

145 days in Mason County

Growing Tips for Yarrow in Mason County

Direct sow Yarrow outdoors after May 15 in Mason 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 →

Frequently Asked Questions

When should I plant Yarrow in Mason County, MI?

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

What planting zone is Mason County, MI?

Mason County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 15 and first fall frost is October 7.

When should I plant Yarrow in Mason County, MI?

In Mason County, MI, plant Yarrow after the last frost (around May 15) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Mason County, MI for Yarrow?

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

Can Yarrow grow in Mason County's climate?

Yes — Yarrow grows well in Mason County's temperate climate. Mason County averages a 145-day frost-free season, with last frost around May 15 and first frost around October 7.

🌱

Your Mason County Garden Planner — Free

A 22-page printable planner built for Mason 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 Mason County, MI. 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.