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When to Plant Yarrow in Dimmit County, TX

Dimmit County, Texas Zone 9a June

Your June game plan for Dimmit County, Texas

Here's what deserves your attention in Dimmit County, Texas this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost February 26
Avg. first frost December 1
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Start harvesting yarrow

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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

Dimmit County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is December 1, giving you a growing season of approximately 278 days.

At an elevation of 2,638 feet, Dimmit County receives approximately 63.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Yarrow during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yarrow root diseases.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Dimmit County, TX (Zone 9a) Year-round
278 days
Last Spring Frost February 26
278 growing days
First Fall Frost December 1

Dimmit County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.3

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Start indoors: Dec 19 Transplant: Jan 30 🌸 Bloom: Mar 27 – Aug 14
Recommended (50%) ✓ Fits season (96 days to spare)
Start indoors: Jan 1 Transplant: Feb 12 🌸 Bloom: Apr 9 – Aug 27
Safe Start (90%) ✓ Fits season (90 days to spare)
Start indoors: Jan 25 Transplant: Mar 8 🌸 Bloom: May 3 – Sep 20

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 Dimmit County

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

Soil pH

Your soil pH (6.5–7.3) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Yarrow.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Succession Planting Yarrow

5
successive plantings in your 278-day season

Sow every 6.9 weeks. Last sowing by Sep 02 to harvest before frost.

Yarrow Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 1.6" 0" ❄️ Dormant
Feb 2.2" 2" 0.2" 💧 Light watering
Mar 2.2" 4" 0" ✅ Rainfall sufficient
Apr 2.2" 6.3" 0" ✅ Rainfall sufficient
May 2.2" 9.1" 0" ✅ Rainfall sufficient
Jun 2.2" 11.3" 0" ✅ Rainfall sufficient
Jul 2.2" 8.6" 0" ✅ Rainfall sufficient
Aug 2.2" 8.1" 0" ✅ Rainfall sufficient
Sep 2.2" 5.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 2.2" 1.4" 0.8" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Dimmit 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 ~1,538 GDD — county provides 5,719 GDD Excellent fit

Yarrow Planting Timeline — Dimmit County, TX

Yarrow Planting Calendar

Activity When Date Range
Start Indoors January 1 Jan 1 – Jan 15
Transplant Outdoors February 12 Feb 12 – Feb 26
Direct Sow February 12 Feb 12 – Mar 5
Bloom April 9 Apr 9 – Aug 27

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Direct Sow
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September
October
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 9a

📆 Growing Season

278 days in Dimmit County

Growing Tips for Yarrow in Dimmit County

Direct sow Yarrow outdoors after February 26 in Dimmit 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 Dimmit County, TX?

Dimmit County is in Zone 9a with an average last frost of February 26. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dimmit County, TX?

Dimmit County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is December 1.

🌱

Your Dimmit County Garden Planner — Free

A 22-page printable planner built for Dimmit County (Zone 9a). 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 Dimmit County, TX. 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.