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When to Plant Yarrow in Zapata County, TX

Zapata County, Texas Zone 9b May

Your May gardening checklist

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

Avg. last frost February 3
Avg. first frost December 14
Soil temp (4") 67°F
Watering Low
Pest pressure High
Daylight 13.3 hrs
  1. Harvest yarrow as they ripen

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

June prep starts now
  • 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.

Zapata County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 14, giving you a growing season of approximately 314 days.

At an elevation of 3,340 feet, Zapata County receives approximately 60.6 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Yarrow may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yarrow root diseases.

Zapata County, TX (Zone 9b) Year-round
314 days
Last Spring Frost February 3
314 growing days
First Fall Frost December 14

Zapata County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (148 days to spare)
Transplant: Jan 24 🍅 Harvest: Apr 25 – Jul 11
Recommended (50%) ✓ Fits season (139 days to spare)
Transplant: Feb 10 🍅 Harvest: May 12 – Jul 28
Safe Start (90%) ✓ Fits season (125 days to spare)
Transplant: Mar 6 🍅 Harvest: Jun 5 – Aug 21

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 Zapata County

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

Soil pH

Your soil pH (6.2–7.6) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.

Soil Texture

The loam soil in Zapata 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

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 1.3" 0" ❄️ Dormant
Feb 2.2" 2.3" 0" ✅ Rainfall sufficient
Mar 2.2" 4.1" 0" ✅ Rainfall sufficient
Apr 2.2" 6.3" 0" ✅ Rainfall sufficient
May 2.2" 7.6" 0" ✅ Rainfall sufficient
Jun 2.2" 10.1" 0" ✅ Rainfall sufficient
Jul 2.2" 8.6" 0" ✅ Rainfall sufficient
Aug 2.2" 7.4" 0" ✅ Rainfall sufficient
Sep 2.2" 6.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 2.2" 1.3" 0.9" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Zapata 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 ~2,861 GDD — county provides 8,583 GDD Excellent fit

Yarrow Planting Timeline — Zapata County, TX

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors February 10 Feb 10 – Feb 24
Harvest May 12 May 12 – Jul 28

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

314 days in Zapata County

Growing Tips for Yarrow in Zapata County

Direct sow Yarrow outdoors after February 03 in Zapata County when soil has warmed and frost danger has passed.

With summer highs reaching 103°F in Zapata County, provide afternoon shade for Yarrow and water deeply in the morning.

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 Zapata County, TX?

Zapata County is in Zone 9b with an average last frost of February 3. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Zapata County, TX?

Zapata County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 14.

🌱

Your Zapata County Garden Planner — Free

A 24-page printable planner built for Zapata County (Zone 9b). 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 Zapata 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.