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When to plant Yarrow in Johnson County, AR

Johnson County's spring Yarrow window runs March 19 through April 9. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Yarrow in Johnson County, AR

Johnson County, Arkansas Zone 8a July

Your July game plan for Johnson County, Arkansas

July is a pivotal month for Johnson County, Arkansas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 26
Avg. first frost November 3
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Bring in the yarrow

    If you can't use it all right away, check the food-preservation section of your planner.

A few tasks this July that'll pay off in August
  • 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.

Johnson County, Arkansas is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 3, giving you a growing season of approximately 222 days.

At an elevation of 1,347 feet, Johnson County receives approximately 49.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Yarrow during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Johnson County, AR (Zone 8a) Long season
222 days
Last Spring Frost March 26
222 growing days
First Fall Frost November 3

Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Jan 24 Transplant: Mar 21 🌸 Bloom: May 23 – Oct 17
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Jan 29 Transplant: Mar 26 🌸 Bloom: May 28 – Oct 22
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Feb 12 Transplant: Apr 9 🌸 Bloom: Jun 11 – Nov 5

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 Johnson County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Yarrow.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

4
successive plantings in your 222-day season

Sow every 6.9 weeks. Last sowing by Aug 05 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 3.8" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 2.2" 4.7" 0" ✅ Rainfall sufficient
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.6" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 4.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 2.2" 4.2" 0" ✅ Rainfall sufficient
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Johnson 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 ~1,369 GDD — county provides 4,051 GDD Excellent fit

Yarrow Planting Timeline — Johnson County, AR

Yarrow Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors March 26 Mar 26 – Apr 9
Direct Sow March 19 Mar 19 – Apr 9
Bloom May 28 May 28 – Oct 22

· 18" apart · Rows 24" apart

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

222 days in Johnson County

Growing Tips for Yarrow in Johnson County

Direct sow Yarrow outdoors after March 26 in Johnson 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 Johnson County, AR?

Johnson County is in Zone 8a with an average last frost of March 26. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnson County, AR?

Johnson County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 3.

When should I plant Yarrow in Johnson County, AR?

In Johnson County, AR, plant Yarrow after the last frost (around March 26) and before the first frost (around November 3). Best results when soil holds above 50°F.

What growing zone is Johnson County, AR for Yarrow?

Johnson County sits in USDA Zone 8a. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Johnson County's climate?

Yes — Yarrow grows well in Johnson County's temperate climate. Johnson County averages a 222-day frost-free season, with last frost around March 26 and first frost around November 3.

🌱

Your Johnson County Garden Planner — Free

A 22-page printable planner built for Johnson County (Zone 8a). 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 Johnson County, AR. 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.