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When to Plant Yarrow in Denton County, TX

Denton County, Texas Zone 8b May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Denton County, Texas this May and put them front and centre. Tackle them in order.

Avg. last frost March 10
Avg. first frost November 20
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
A few tasks this May that'll pay off in June
  • First harvests: yarrow

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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.

Denton County, Texas is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 1,848 feet, Denton County receives approximately 64.5 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Yarrow during the growing season. Clay soil retains moisture well for Yarrow, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yarrow root diseases.

Denton County, TX (Zone 8b) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20
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Denton County Soil Profile

Soil Type

Clay

Soil pH

6.7-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Transplant: Mar 9 🍅 Harvest: Jun 8 – Aug 24
Recommended (50%) ✓ Fits season (80 days to spare)
Transplant: Mar 17 🍅 Harvest: Jun 16 – Sep 1
Safe Start (90%) ✓ Fits season (65 days to spare)
Transplant: Apr 18 🍅 Harvest: Jul 18 – Oct 3

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 Denton County

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

Soil pH

Your soil pH (6.7–8.1) is more alkaline than Yarrow prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (40% clay) in Denton County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Drainage

Yarrow prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (3.2%). 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.4" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 2.2" 4.2" 0" ✅ Rainfall sufficient
Apr 2.2" 7.5" 0" ✅ Rainfall sufficient
May 2.2" 9.6" 0" ✅ Rainfall sufficient
Jun 2.2" 10.2" 0" ✅ Rainfall sufficient
Jul 2.2" 7.6" 0" ✅ Rainfall sufficient
Aug 2.2" 8" 0" ✅ Rainfall sufficient
Sep 2.2" 6.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Denton 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 ~1,838 GDD — county provides 4,462 GDD Excellent fit

Yarrow Planting Timeline — Denton County, TX

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors March 17 Mar 17 – Mar 31
Harvest June 16 Jun 16 – Sep 1

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April
May
June Harvest
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

255 days in Denton County

Growing Tips for Yarrow in Denton County

Direct sow Yarrow outdoors after March 10 in Denton County when soil has warmed and frost danger has passed.

With Denton County's clay soil (40% clay), work in 3-4 inches of compost before planting Yarrow. Avoid tilling when soil is wet to prevent compaction.

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

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 Denton County, TX?

Denton County is in Zone 8b with an average last frost of March 10. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Denton County, TX?

Denton County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 20.

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Your Denton County Garden Planner — Free

A 24-page printable planner built for Denton County (Zone 8b). 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 Denton County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.