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When to Plant Lavender in Jefferson County, TX

Jefferson County, Texas Zone 9b May

May in the garden — Jefferson County, Texas

Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 13
Avg. first frost December 6
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest lavender as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Before June arrives, get these ready
  • 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.

Jefferson County, Texas is in USDA Zone 9b. The average last spring frost is February 13 and the first fall frost is December 6, giving you a growing season of approximately 296 days.

At an elevation of 349 feet, Jefferson County receives approximately 64.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 101°F, so Lavender may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lavender will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lavender root diseases.

Jefferson County, TX (Zone 9b) Year-round
296 days
Last Spring Frost February 13
296 growing days
First Fall Frost December 6

Jefferson County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Jan 31 🍅 Harvest: May 2 – Oct 3
Recommended (50%) ✓ Fits season (44 days to spare)
Transplant: Feb 20 🍅 Harvest: May 22 – Oct 23
Safe Start (90%) ✓ Fits season (41 days to spare)
Transplant: Mar 13 🍅 Harvest: Jun 12 – Nov 13

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 Jefferson County

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

Soil pH

Your soil pH (5.4–6.5) is more acidic than Lavender prefers (6.5–8.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). 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
0.9″/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" 2.1" 0" ✅ Rainfall sufficient
Mar 1.3" 4.4" 0" ✅ Rainfall sufficient
Apr 1.3" 6.3" 0" ✅ Rainfall sufficient
May 1.3" 9.8" 0" ✅ Rainfall sufficient
Jun 1.3" 10.7" 0" ✅ Rainfall sufficient
Jul 1.3" 8.8" 0" ✅ Rainfall sufficient
Aug 1.3" 6.6" 0" ✅ Rainfall sufficient
Sep 1.3" 6.6" 0" ✅ Rainfall sufficient
Oct 1.3" 4.4" 0" ✅ Rainfall sufficient
Nov 1.3" 2.1" 0" ✅ Rainfall sufficient
Dec 1.3" 1.6" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Jefferson 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 ~3,734 GDD — county provides 7,647 GDD Excellent fit

Lavender Planting Timeline — Jefferson County, TX

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors February 20 Feb 20 – Mar 6
Harvest May 22 May 22 – Oct 23

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

Month-by-Month Timeline

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

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: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

296 days in Jefferson County

Growing Tips for Lavender in Jefferson County

Direct sow Lavender outdoors after February 13 in Jefferson County when soil has warmed and frost danger has passed.

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

With summer highs reaching 101°F in Jefferson County, provide afternoon shade for Lavender and water deeply in the morning.

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

Jefferson County is in Zone 9b with an average last frost of February 13. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, TX?

Jefferson County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 13 and first fall frost is December 6.

🌱

Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson 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 Jefferson 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.