Blog

When to Plant Lavender in Pend Oreille County, WA

Lavender
Pend Oreille County, Washington Zone 6a August

Your August planting checklist for Pend Oreille County, Washington

August is a pivotal month for Pend Oreille County, Washington gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 10
Avg. first frost September 23
Soil temp (4") 67°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Basket week: lavender

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of September
  • First harvests: lavender

Instant PDF download. No spam, unsubscribe any time.

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.

Pend Oreille County, Washington is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is September 23, giving you a growing season of approximately 136 days.

At an elevation of 3,807 feet, Pend Oreille County receives approximately 13.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°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
Pend Oreille County, WA (Zone 6a) Short season
136 days
Last Spring Frost May 10
136 growing days
First Fall Frost September 23

Pend Oreille County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.6

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 20 Transplant: May 15 🌸 Bloom: Jul 24 – Sep 18
Recommended (50%) ✗ May not fit
Start indoors: Mar 1 Transplant: May 24 🌸 Bloom: Aug 2 – Sep 27
Safe Start (90%) ✗ May not fit
Start indoors: Mar 22 Transplant: Jun 14 🌸 Bloom: Aug 23 – Oct 18

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 Pend Oreille County

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

Soil pH

Your soil pH (5.3–6.6) is more acidic than Lavender prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Lavender.

Organic Matter

Organic matter is excellent (5.0%) — Lavender will thrive.

How to Plant Lavender

0.5"
Planting Depth
18"
Between Plants
24"
Between Rows

Lavender Water Budget

Plant needs
0.3″/week
Rainfall provides
0.4″/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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 0.9" 0" ❄️ Dormant
May 1.3" 0.8" 0.5" 💧 Light watering
Jun 1.3" 0.5" 0.8" 🚿 Regular watering
Jul 1.3" 0.2" 1.1" 🚿 Regular watering
Aug 1.3" 0.2" 1.1" 🚿 Regular watering
Sep 1.3" 0.6" 0.7" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Pend Oreille 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 ~1,522 GDD — county provides 1,972 GDD Good fit

Lavender Planting Timeline — Pend Oreille County, WA

Lavender Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 24 May 24 – Jun 7
Bloom August 2 Aug 2 – Sep 27

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors
June Transplant Outdoors
July
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_acidic

🗺️ USDA Zone

Zone 6a

📆 Growing Season

136 days in Pend Oreille County

Growing Tips for Lavender in Pend Oreille County

Direct sow Lavender outdoors after May 10 in Pend Oreille 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 Pend Oreille County, WA?

Pend Oreille County is in Zone 6a with an average last frost of May 10. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pend Oreille County, WA?

Pend Oreille County, Washington is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is September 23.

🌱

Your Pend Oreille County Garden Planner — Free

A 22-page printable planner built for Pend Oreille County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Pend Oreille County, WA. Local conditions may vary. Last updated: August 2026.

Sources & credits

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