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When to Plant Lavender in Washington County, UT

Lavender
Washington County, Utah Zone 8b June

What to do in June

Welcome to June in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 6
Avg. first frost November 1
Soil temp (4") 73°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Start lavender under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. It's harvest week for lavender

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Looking ahead to July
  • 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.

Washington County, Utah is in USDA Zone 8b. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 3,524 feet, Washington County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Lavender during the growing season. With low rainfall, drip irrigation is essential for growing Lavender successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Washington County, UT (Zone 8b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✓ Fits season (49 days to spare)
Start indoors: Jan 16 Transplant: Mar 13 🌸 Bloom: May 22 – Aug 28
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Feb 9 Transplant: Apr 6 🌸 Bloom: Jun 15 – Sep 21
Safe Start (90%) ✓ Fits season (10 days to spare)
Start indoors: Apr 1 Transplant: May 27 🌸 Bloom: Aug 5 – Nov 11

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 Washington County

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

Soil pH

Your soil pH (6.7–8.0) overlaps with Lavender's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Lavender.

Organic Matter

Organic matter is moderate (2.4%). 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
0.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 301 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.3" 1.2" 0.1" 💧 Light watering
May 1.3" 1.4" 0" ✅ Rainfall sufficient
Jun 1.3" 0.9" 0.4" 💧 Light watering
Jul 1.3" 1.2" 0.1" 💧 Light watering
Aug 1.3" 1.4" 0" ✅ Rainfall sufficient
Sep 1.3" 0.9" 0.4" 💧 Light watering
Oct 1.3" 1.2" 0.1" 💧 Light watering
Nov 1.3" 1" 0.3" 💧 Light watering
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Washington 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 ~1,838 GDD — county provides 3,657 GDD Excellent fit

Lavender Planting Timeline — Washington County, UT

Lavender Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 – Feb 23
Transplant Outdoors April 6 Apr 6 – Apr 20
Bloom June 15 Jun 15 – Sep 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

209 days in Washington County

Growing Tips for Lavender in Washington County

Direct sow Lavender outdoors after April 06 in Washington County when soil has warmed and frost danger has passed.

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 Washington County, UT?

Washington County is in Zone 8b with an average last frost of April 6. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, UT?

Washington County, Utah is in USDA Hardiness Zone 8b. The average last spring frost is April 6 and first fall frost is November 1.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington 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 Washington County, UT. 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.