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When to Plant Lavender in Starr County, TX

Starr County, Texas Zone 9b May

Your May planting checklist for Starr County, Texas

May is a pivotal month for Starr County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 3
Avg. first frost December 16
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.3 hrs
  1. Bring in the lavender

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

Looking ahead to June
  • First harvests: lavender

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Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Starr County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 16, giving you a growing season of approximately 316 days.

At an elevation of 2,451 feet, Starr County receives approximately 55.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98°F, so Lavender may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lavender root diseases.

Starr County, TX (Zone 9b) Year-round
316 days
Last Spring Frost February 3
316 growing days
First Fall Frost December 16
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Starr County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (74 days to spare)
Transplant: Jan 25 🍅 Harvest: Apr 26 – Sep 27
Recommended (50%) ✓ Fits season (64 days to spare)
Transplant: Feb 10 🍅 Harvest: May 12 – Oct 13
Safe Start (90%) ✓ Fits season (45 days to spare)
Transplant: Mar 10 🍅 Harvest: Jun 9 – Nov 10

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 Starr County

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

Soil pH

Your soil pH (6.8–7.5) is within Lavender's preferred range (6.5–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Lavender.

How to Plant Lavender

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

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.7″/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 Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.3" 1.9" 0" ✅ Rainfall sufficient
Mar 1.3" 3.4" 0" ✅ Rainfall sufficient
Apr 1.3" 6.6" 0" ✅ Rainfall sufficient
May 1.3" 8.8" 0" ✅ Rainfall sufficient
Jun 1.3" 7.6" 0" ✅ Rainfall sufficient
Jul 1.3" 7" 0" ✅ Rainfall sufficient
Aug 1.3" 6.4" 0" ✅ Rainfall sufficient
Sep 1.3" 4.9" 0" ✅ Rainfall sufficient
Oct 1.3" 4" 0" ✅ Rainfall sufficient
Nov 1.3" 1.6" 0" ✅ Rainfall sufficient
Dec 1.3" 1.6" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Starr County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lavender 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.

Lavender needs ~3,408 GDD — county provides 7,449 GDD Excellent fit

Lavender Planting Timeline — Starr County, TX

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors February 10 Feb 10 – Feb 24
Harvest May 12 May 12 – Oct 13

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 Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

90–200 days

🧪 Soil pH

Needs 6.5–8 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

316 days in Starr County

Growing Tips for Lavender in Starr County

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

With summer highs reaching 98°F in Starr County, provide afternoon shade for Lavender and water deeply in the morning.

With 55" of annual rainfall in Starr County, ensure good drainage for Lavender — excess moisture can promote root rot and fungal diseases.

General growing tips

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Starr County, TX?

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

What planting zone is Starr County, TX?

Starr County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 16.

🌱

Your Starr County Garden Planner — Free

A 24-page printable planner built for Starr 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 Starr 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.