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When to Plant Yarrow in Clark County, KS

Yarrow is a drought-tolerant perennial herb with feathery foliage and flat-topped flower clusters in white, yellow, pink, or red. It attracts beneficial insects and is used in herbal medicine.

Clark County, Kansas is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.

At an elevation of 867 feet, Clark County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 92ยฐF, providing good warmth for Yarrow during the growing season.

Clark County, KS (Zone 6b) Moderate season
189 days
Last Spring Frost April 16
189 growing days
First Fall Frost October 22

Clark County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Transplant: Apr 18 🍅 Harvest: Jul 18 – Oct 3
Recommended (50%) ✓ Fits season (14 days to spare)
Transplant: Apr 23 🍅 Harvest: Jul 23 – Oct 8
Safe Start (90%) ✓ Fits season (13 days to spare)
Transplant: May 7 🍅 Harvest: Aug 6 – Oct 22

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 Clark County

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

Soil pH

Your soil pH (6.8โ€“7.6) is more alkaline than Yarrow prefers (5.5โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Clark County is excellent for Yarrow โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Yarrow.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Yarrow.

How to Plant Yarrow

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 312 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr 2.2" 2" 0.2" ๐Ÿ’ง Light watering
May 2.2" 3.4" 0" โœ… Rainfall sufficient
Jun 2.2" 3.7" 0" โœ… Rainfall sufficient
Jul 2.2" 3.1" 0" โœ… Rainfall sufficient
Aug 2.2" 3" 0" โœ… Rainfall sufficient
Sep 2.2" 1.9" 0.3" ๐Ÿ’ง Light watering
Oct 2.2" 1.2" 1" ๐Ÿ’ง Light watering
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Clark County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,995 GDD — county provides 3,591 GDD Excellent fit

Yarrow Planting Timeline โ€” Clark County, KS

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Harvest July 23 Jul 23 โ€“ Oct 8

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

189 days in Clark County

Growing Tips for Yarrow in Clark County

Direct sow Yarrow outdoors after April 16 in Clark 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.

Clark County receives only 22" of rain annually. Yarrow needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow or start from divisions. Yarrow thrives in poor soil and is very drought-tolerant. Deadhead to encourage reblooming. Divide clumps every 3 years.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Yarrow in Clark County, KS?

Clark County is in Zone 6b with an average last frost of April 16. Plan your Yarrow planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clark County, KS?

Clark County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clark County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clark County, KS. Local conditions may vary. Last updated: April 2026.