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When to Plant Lavender in Dallam County, TX

Lavender
Dallam County, Texas Zone 6b June

This month in Dallam County, Texas

A quick June briefing for Dallam County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 26
Avg. first frost October 14
Soil temp (4") 66°F
Watering High
Pest pressure High
Daylight 14.5 hrs
July prep starts now
  • Starting indoors: lavender
  • First harvests: lavender

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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.

Dallam County, Texas is in USDA Zone 6b. The average last spring frost is April 26 and the first fall frost is October 14, giving you a growing season of approximately 171 days.

At an elevation of 3,388 feet, Dallam County receives approximately 54.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°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
Dallam County, TX (Zone 6b) Moderate season
171 days
Last Spring Frost April 26
171 growing days
First Fall Frost October 14

Dallam County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.9-8.4

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Feb 9 Transplant: May 4 🌸 Bloom: Jul 13 – Sep 7
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Feb 15 Transplant: May 10 🌸 Bloom: Jul 19 – Sep 13
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Feb 27 Transplant: May 22 🌸 Bloom: Jul 31 – Sep 25

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 Dallam County

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

Soil pH

Your soil pH (7.9–8.4) is more alkaline than Lavender prefers (6.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Dallam 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 low (1.1%). Add 2-3 inches of compost before planting 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
1.3″/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 4" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 1.3" 1.7" 0" ✅ Rainfall sufficient
May 1.3" 1" 0.3" 💧 Light watering
Jun 1.3" 1.7" 0" ✅ Rainfall sufficient
Jul 1.3" 9.9" 0" ✅ Rainfall sufficient
Aug 1.3" 11.7" 0" ✅ Rainfall sufficient
Sep 1.3" 8" 0" ✅ Rainfall sufficient
Oct 1.3" 4" 0" ✅ Rainfall sufficient
Nov 3.3" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dallam 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 ~2,310 GDD — county provides 3,762 GDD Excellent fit

Lavender Planting Timeline — Dallam County, TX

Lavender Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors May 10 May 10 – May 24
Bloom July 19 Jul 19 – Sep 13

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

Month-by-Month Timeline

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

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_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

171 days in Dallam County

Growing Tips for Lavender in Dallam County

Direct sow Lavender outdoors after April 26 in Dallam County when soil has warmed and frost danger has passed.

Sandy soil in Dallam 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 96°F in Dallam County, provide afternoon shade for Lavender and water deeply in the morning.

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 Dallam County, TX?

Dallam County is in Zone 6b with an average last frost of April 26. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dallam County, TX?

Dallam County, Texas is in USDA Hardiness Zone 6b. The average last spring frost is April 26 and first fall frost is October 14.

🌱

Your Dallam County Garden Planner — Free

A 22-page printable planner built for Dallam County (Zone 6b). 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 Dallam 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.