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When to Plant Lavender in Collin County, TX

Collin County, Texas Zone 8b May

May in Collin County, Texas — your action list

Each item below is timed to Collin County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 10
Avg. first frost November 20
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
To set up a strong June, finish these tasks
  • 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.

Collin 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 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94°F, providing good warmth for Lavender during the growing season. Clay soil retains moisture well for Lavender, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lavender root diseases.

Collin 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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Collin County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Transplant: Mar 9 🍅 Harvest: Jun 8 – Nov 9
Recommended (50%) ✓ Fits season (3 days to spare)
Transplant: Mar 17 🍅 Harvest: Jun 16 – Nov 17
Safe Start (90%) ✗ May not fit
Transplant: Apr 18 🍅 Harvest: Jul 18 – Dec 19

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 Collin County

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

Soil pH

Your soil pH (7.3–7.8) is within Lavender's preferred range (6.5–8.0).

Soil Texture

Heavy clay soil (43% clay) in Collin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (2.7%). 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
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 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 1.8" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 1.3" 4.3" 0" ✅ Rainfall sufficient
Apr 1.3" 6.9" 0" ✅ Rainfall sufficient
May 1.3" 10.2" 0" ✅ Rainfall sufficient
Jun 1.3" 9.9" 0" ✅ Rainfall sufficient
Jul 1.3" 7.3" 0" ✅ Rainfall sufficient
Aug 1.3" 8.4" 0" ✅ Rainfall sufficient
Sep 1.3" 6.5" 0" ✅ Rainfall sufficient
Oct 1.3" 3.9" 0" ✅ Rainfall sufficient
Nov 1.3" 2.2" 0" ✅ Rainfall sufficient
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Collin 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 ~2,972 GDD — county provides 5,227 GDD Excellent fit

Lavender Planting Timeline — Collin County, TX

Lavender Planting Calendar

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

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 Harvest
November Harvest
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 8b

📆 Growing Season

255 days in Collin County

Growing Tips for Lavender in Collin County

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

With Collin County's clay soil (43% clay), work in 3-4 inches of compost before planting Lavender. Avoid tilling when soil is wet to prevent compaction.

With 65" of annual rainfall in Collin 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 Collin County, TX?

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

What planting zone is Collin County, TX?

Collin 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 Collin County Garden Planner — Free

A 24-page printable planner built for Collin 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 Collin 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.