When to Plant Lavender in Wahkiakum County, WA
What to do in May
Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.
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.
Wahkiakum County, Washington is in USDA Zone 8b. The average last spring frost is April 13 and the first fall frost is November 4, giving you a growing season of approximately 205 days.
At an elevation of 180 feet, Wahkiakum County receives approximately 35.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Lavender during the growing season.
Wahkiakum County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.3
Drainage
Well Drained
Plant Planting Risk Windows
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 Wahkiakum County
How your county's soil matches Lavender's growing requirements.
Soil pH
Your soil pH (5.4–6.3) is more acidic than Lavender prefers (6.5–8.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Wahkiakum 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
Plant Water Budget
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 | — | 4.2" | 0" | ❄️ Dormant |
| Mar | — | 3.6" | 0" | ❄️ Dormant |
| Apr | 1.3" | 2.6" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 1.8" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 1.4" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 0.6" | 0.7" | 🚿 Regular watering |
| Aug | 1.3" | 0.7" | 0.6" | 💧 Light watering |
| Sep | 1.3" | 1.4" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | 1.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Dec | — | 5.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Wahkiakum 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 Planting Timeline — Wahkiakum County, WA
Lavender Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Harvest | July 20 | Jul 20 – Dec 21 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
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
205 days in Wahkiakum County
Growing Tips for Lavender in Wahkiakum County
Direct sow Lavender outdoors after April 13 in Wahkiakum County when soil has warmed and frost danger has passed.
Your 205.0-day growing season in Wahkiakum 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 →
Lavender in Other Locations
Frequently Asked Questions
When should I plant Lavender in Wahkiakum County, WA?
Wahkiakum County is in Zone 8b with an average last frost of April 13. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.
What planting zone is Wahkiakum County, WA?
Wahkiakum County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 13 and first fall frost is November 4.
Your Wahkiakum County Garden Planner — Free
A 24-page printable planner built for Wahkiakum 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.