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When to Plant Yarrow in Galveston County, TX

Galveston County, Texas Zone 9b May

May in Galveston County, Texas — your action list

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

Avg. last frost February 5
Avg. first frost December 7
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Basket week: yarrow

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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.

Galveston County, Texas is in USDA Zone 9b. The average last spring frost is February 5 and the first fall frost is December 7, giving you a growing season of approximately 305 days.

At an elevation of 9 feet, Galveston County receives approximately 72.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 100°F, so Yarrow may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Yarrow will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yarrow root diseases.

Galveston County, TX (Zone 9b) Year-round
305 days
Last Spring Frost February 5
305 growing days
First Fall Frost December 7

Galveston County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (142 days to spare)
Transplant: Jan 25 🍅 Harvest: Apr 26 – Jul 12
Recommended (50%) ✓ Fits season (130 days to spare)
Transplant: Feb 12 🍅 Harvest: May 14 – Jul 30
Safe Start (90%) ✓ Fits season (117 days to spare)
Transplant: Mar 13 🍅 Harvest: Jun 12 – Aug 28

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 Galveston County

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

Soil pH

Your soil pH (5.7–6.5) is within Yarrow's preferred range (5.5–7.0).

Soil Texture

Sandy soil in Galveston County warms quickly in spring but drains fast. Yarrow will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.1%). 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
1.0″/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 2.1" 0" ❄️ Dormant
Feb 2.2" 2.2" 0" ✅ Rainfall sufficient
Mar 2.2" 5.4" 0" ✅ Rainfall sufficient
Apr 2.2" 8.2" 0" ✅ Rainfall sufficient
May 2.2" 10.4" 0" ✅ Rainfall sufficient
Jun 2.2" 10.9" 0" ✅ Rainfall sufficient
Jul 2.2" 8.7" 0" ✅ Rainfall sufficient
Aug 2.2" 8.6" 0" ✅ Rainfall sufficient
Sep 2.2" 6.2" 0" ✅ Rainfall sufficient
Oct 2.2" 5.2" 0" ✅ Rainfall sufficient
Nov 2.2" 2.6" 0" ✅ Rainfall sufficient
Dec 2.2" 1.9" 0.3" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Galveston 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 ~2,625 GDD — county provides 7,650 GDD Excellent fit

Yarrow Planting Timeline — Galveston County, TX

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors February 12 Feb 12 – Feb 26
Harvest May 14 May 14 – Jul 30

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: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

305 days in Galveston County

Growing Tips for Yarrow in Galveston County

Direct sow Yarrow outdoors after February 05 in Galveston County when soil has warmed and frost danger has passed.

Sandy soil in Galveston County dries quickly — mulch Yarrow with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 100°F in Galveston 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 Galveston County, TX?

Galveston County is in Zone 9b with an average last frost of February 5. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Galveston County, TX?

Galveston County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 5 and first fall frost is December 7.

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Your Galveston County Garden Planner — Free

A 24-page printable planner built for Galveston 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 Galveston 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.