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When to plant Yarrow in Danforth, ME

Spring Yarrow in Danforth goes in May 9–May 30, once nighttime temps stop dipping near freezing.

When to Plant Yarrow in Danforth, ME

Washington County, Maine Zone 5b July

July in Washington County, Maine — your action list

Here's what deserves your attention in Washington County, Maine this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost May 9
Avg. first frost October 7
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
  1. Time to start yarrow inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Before August arrives, get these ready
  • 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.

Danforth, Maine is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 7, giving you a growing season of approximately 151 days.

At an elevation of 1,184 feet, Washington County receives approximately 43.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Yarrow to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Danforth, ME (Zone 5b) Moderate season
151 days
Last Spring Frost May 9
151 growing days
First Fall Frost October 7

Danforth Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.5

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 27 Transplant: May 15 🌸 Bloom: Jul 24 – Nov 6
Recommended (50%) ✗ May not fit
Start indoors: Mar 7 Transplant: May 23 🌸 Bloom: Aug 1 – Nov 14
Safe Start (90%) ✗ May not fit
Start indoors: Mar 25 Transplant: Jun 10 🌸 Bloom: Aug 19 – Dec 2

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 Danforth

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

Soil pH

Your soil pH (5.0–6.5) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Yarrow.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

2
successive plantings in your 151-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
1.2″/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 3.2" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.7" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.8" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 3.4" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Washington 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 ~750 GDD — county provides 1,510 GDD Excellent fit

Yarrow Planting Timeline — Danforth, ME

Yarrow Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 9 May 9 – May 30
Bloom August 1 Aug 1 – Nov 14

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors
July
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 5b

📆 Growing Season

151 days in Washington County

Growing Tips for Yarrow in Danforth

Direct sow Yarrow outdoors after May 09 in Washington 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 Danforth, ME?

In Danforth, ME, plant Yarrow after the last frost (around May 9) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Danforth, ME for Yarrow?

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

Can Yarrow grow in Danforth's climate?

Yes — Yarrow grows well in Danforth's temperate climate. Danforth averages a 151-day frost-free season, with last frost around May 9 and first frost around October 7.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 5b). 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 Washington County, ME. Local conditions may vary. Last updated: July 2026.