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When to plant Yarrow in Kent County, DE

In Kent County, plant Yarrow in spring between March 26 and April 16, once soil temps hold above 50°F. Kent County's last frost averages April 2, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between and — roughly 60–90 days before the first frost on November 4.

When to Plant Yarrow in Kent County, DE

Kent County, Delaware Zone 7b June

This month in Kent County, Delaware

Here's what deserves your attention in Kent County, Delaware this month. Everything below is tailored to Zone 7b and timed around your local frost dates.

Avg. last frost April 2
Avg. first frost November 4
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Get yarrow seeds going inside

    These need a head start before your last frost (April 2). Sow into cells now so you're ready to transplant in a few weeks.

  2. It's harvest week for yarrow

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July prep starts now
  • 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.

Kent County, Delaware is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 4, giving you a growing season of approximately 216 days.

At an elevation of 128 feet, Kent County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Yarrow during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Kent County, DE (Zone 7b) Long season
216 days
Last Spring Frost April 2
216 growing days
First Fall Frost November 4

Kent County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Start indoors: Jan 24 Transplant: Apr 4 🌸 Bloom: Jun 6 – Oct 24
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Jan 29 Transplant: Apr 9 🌸 Bloom: Jun 11 – Oct 29
Safe Start (90%) ✓ Fits season (1 days to spare)
Start indoors: Feb 14 Transplant: Apr 25 🌸 Bloom: Jun 27 – Nov 14

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 Kent County

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

Soil pH

Your soil pH (5.8–6.8) is within Yarrow's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Yarrow.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

4
successive plantings in your 216-day season

Sow every 6.9 weeks. Last sowing by Aug 06 to harvest before frost.

Yarrow Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 4" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 2.2" 4" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 3.9" 0" ✅ Rainfall sufficient
Jul 2.2" 5.6" 0" ✅ Rainfall sufficient
Aug 2.2" 4.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.7" 0" ✅ Rainfall sufficient
Oct 2.2" 4" 0" ✅ Rainfall sufficient
Nov 2.2" 3.5" 0" ✅ Rainfall sufficient
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Kent 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 ~1,200 GDD — county provides 3,456 GDD Excellent fit

Yarrow Planting Timeline — Kent County, DE

Yarrow Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow March 26 Mar 26 – Apr 16
Bloom June 11 Jun 11 – Oct 29

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Direct Sow
April Transplant Outdoors Direct Sow
May
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
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 7b

📆 Growing Season

216 days in Kent County

Growing Tips for Yarrow in Kent County

Direct sow Yarrow outdoors after April 02 in Kent 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 Kent County, DE?

Kent County is in Zone 7b with an average last frost of April 2. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kent County, DE?

Kent County, Delaware is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 4.

When should I plant Yarrow in Kent County, DE?

In Kent County, DE, plant Yarrow after the last frost (around April 2) and before the first frost (around November 4). Best results when soil holds above 50°F.

What growing zone is Kent County, DE for Yarrow?

Kent County sits in USDA Zone 7b. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Kent County's climate?

Yes — Yarrow grows well in Kent County's temperate climate. Kent County averages a 216-day frost-free season, with last frost around April 2 and first frost around November 4.

🌱

Your Kent County Garden Planner — Free

A 22-page printable planner built for Kent County (Zone 7b). 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 Kent County, DE. 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.