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When to Plant Lavender in Harris County, TX

Lavender
Harris County, Texas Zone 9b June

Top priorities for Harris County, Texas gardeners in June

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

Avg. last frost February 14
Avg. first frost December 4
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Pick lavender

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

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Lavender (Lavandula angustifolia) is a fragrant Mediterranean sub-shrub prized for its silver-gray foliage and intensely aromatic purple flower spikes. A classic companion for roses and an unmatched pollinator magnet, lavender thrives in the exact conditions that challenge many plants: poor, rocky, alkaline soil with excellent drainage and full sun. English lavender is the most cold-hardy species, reliably perennial in Zones 5–9. Fresh or dried flowers are widely used in sachets, essential oils, culinary applications, and dried arrangements.

Harris County, Texas is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.

At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°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.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Harris County, TX (Zone 9b) Year-round
293 days
Last Spring Frost February 14
293 growing days
First Fall Frost December 4
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Harris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✓ Fits season (160 days to spare)
Start indoors: Dec 12 Transplant: Jan 16 🌸 Bloom: Mar 27 – Jun 19
Recommended (50%) ✓ Fits season (160 days to spare)
Start indoors: Dec 20 Transplant: Jan 24 🌸 Bloom: Apr 4 – Jun 27
Safe Start (90%) ✓ Fits season (156 days to spare)
Start indoors: Jan 11 Transplant: Feb 15 🌸 Bloom: Apr 26 – Jul 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 Harris County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Lavender prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Harris 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
18"
Between Plants
24"
Between Rows

Lavender Water Budget

Plant needs
0.3″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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" 2.7" 0" ✅ Rainfall sufficient
Mar 1.3" 3.8" 0" ✅ Rainfall sufficient
Apr 1.3" 7.4" 0" ✅ Rainfall sufficient
May 1.3" 10.1" 0" ✅ Rainfall sufficient
Jun 1.3" 10" 0" ✅ Rainfall sufficient
Jul 1.3" 9.6" 0" ✅ Rainfall sufficient
Aug 1.3" 8.5" 0" ✅ Rainfall sufficient
Sep 1.3" 6.3" 0" ✅ Rainfall sufficient
Oct 1.3" 3.9" 0" ✅ Rainfall sufficient
Nov 1.3" 2.2" 0" ✅ Rainfall sufficient
Dec 1.3" 1.6" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Harris 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 ~2,782 GDD — county provides 7,791 GDD Excellent fit

Lavender Planting Timeline — Harris County, TX

Lavender Planting Calendar

Activity When Date Range
Start Indoors December 20 Dec 20 – Jan 3
Transplant Outdoors January 24 Jan 24 – Feb 7
Bloom April 4 Apr 4 – Jun 27

Plant 0.5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors
February Transplant Outdoors
March
April Bloom
May Bloom
June Bloom
July
August
September
October
November
December Start Indoors
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

293 days in Harris County

Growing Tips for Lavender in Harris County

Direct sow Lavender outdoors after February 14 in Harris County when soil has warmed and frost danger has passed.

Sandy soil in Harris 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 102°F in Harris County, provide afternoon shade for Lavender and water deeply in the morning.

With 68" of annual rainfall in Harris County, ensure good drainage for Lavender — excess moisture can promote root rot and fungal diseases.

General growing tips

The single most important requirement for lavender success is excellent drainage — it will rot in heavy clay or wet winter soils before cold alone kills it. Amend with coarse sand or fine gravel if needed; raised beds work well in Zones 5–6. Start from rooted cuttings or transplants rather than seed for named cultivars. Transplant after last frost when soil is reliably warm (55°F+). Avoid rich or overly moist soils. Prune lightly after each flush of bloom, but never cut into old wood below the green growth zone — it will not regenerate from leafless woody stems. In Zones 5–6, mulch lightly with gravel (not bark/organic material which traps moisture) around the crown for winter protection. Year 2+ plants develop into full, mature shrubs with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Harris County, TX?

Harris County is in Zone 9b with an average last frost of February 14. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harris County, TX?

Harris County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 4.

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Your Harris County Garden Planner — Free

A 22-page printable planner built for Harris 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 Harris County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.