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When to Plant Lavender in Thurston County, WA

Thurston County, Washington Zone 8b May

Your May planting checklist for Thurston County, Washington

Your garden in Thurston County, Washington is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 15
Avg. first frost October 29
Soil temp (4") 70°F
Watering High
Pest pressure High
Daylight 14.8 hrs

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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.

Thurston County, Washington is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 29, giving you a growing season of approximately 197 days.

At an elevation of 213 feet, Thurston County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Lavender during the growing season.

Thurston County, WA (Zone 8b) Moderate season
197 days
Last Spring Frost April 15
197 growing days
First Fall Frost October 29
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Thurston County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 13 🍅 Harvest: Jul 13 – Dec 14
Recommended (50%) ✗ May not fit
Transplant: Apr 22 🍅 Harvest: Jul 22 – Dec 23
Safe Start (90%) ✓ Fits season (312 days to spare)
Transplant: May 16 🍅 Harvest: Aug 15 – Jan 16

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 Thurston 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 (6.5–8.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Lavender will thrive.

How to Plant Lavender

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.8″/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 4.9" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 1.3" 2.7" 0" ✅ Rainfall sufficient
May 1.3" 2.2" 0" ✅ Rainfall sufficient
Jun 1.3" 1.4" 0" ✅ Rainfall sufficient
Jul 1.3" 0.7" 0.6" 💧 Light watering
Aug 1.3" 0.7" 0.6" 💧 Light watering
Sep 1.3" 1.7" 0" ✅ Rainfall sufficient
Oct 1.3" 3" 0" ✅ Rainfall sufficient
Nov 5.3" 0" ❄️ Dormant
Dec 6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Thurston 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 ~2,429 GDD — county provides 3,299 GDD Excellent fit

Lavender Planting Timeline — Thurston County, WA

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors April 22 Apr 22 – May 6
Harvest July 22 Jul 22 – Dec 23

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June
July Harvest
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest
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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 8b

📆 Growing Season

197 days in Thurston County

Growing Tips for Lavender in Thurston County

Direct sow Lavender outdoors after April 15 in Thurston County when soil has warmed and frost danger has passed.

Your 197.0-day growing season in Thurston County is tight for Lavender (90.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Thurston County, WA?

Thurston County is in Zone 8b with an average last frost of April 15. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Thurston County, WA?

Thurston County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 29.

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Your Thurston County Garden Planner — Free

A 24-page printable planner built for Thurston 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 Thurston County, WA. 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.