When to Plant Thyme in Clark County, WA
Your May game plan for Clark County, Washington
Here's what deserves your attention in Clark County, Washington this month. Everything below is tailored to Zone 8b and timed around your local frost dates.
Coming up in June — start thinking about
- First harvests: thyme
Thyme is a low-growing perennial herb with tiny, aromatic leaves and a warm, earthy flavor. It is one of the most versatile culinary and medicinal herbs.
Clark County, Washington is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.
At an elevation of 482 feet, Clark County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Thyme during the growing season.
Clark 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 Clark County
How your county's soil matches Thyme's growing requirements.
Soil pH
Your soil pH (5.4–6.3) is more acidic than Thyme prefers (6.0–8.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Clark County is excellent for Thyme — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Thyme.
Organic Matter
Organic matter is excellent (4.8%) — Thyme will thrive.
How to Plant Thyme
Succession Planting Thyme
Sow every 8 weeks. Last sowing by Jul 29 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Thyme
Thyme 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 | Thyme Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.4" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | — | 4" | 0" | ❄️ Dormant |
| Apr | 1.3" | 2.6" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 2.5" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 1.7" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 0.6" | 0.7" | 🚿 Regular watering |
| Aug | 1.3" | 0.8" | 0.5" | 💧 Light watering |
| Sep | 1.3" | 1.5" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 3.1" | 0" | ✅ Rainfall sufficient |
| Nov | — | 5.9" | 0" | ❄️ Dormant |
| Dec | — | 7.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clark County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Thyme 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.
Thyme Planting Timeline — Clark County, WA
Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Harvest | June 30 | Jun 30 – Sep 1 |
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 | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–8 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
196 days in Clark County
Growing Tips for Thyme in Clark County
Direct sow Thyme outdoors after April 14 in Clark County when soil has warmed and frost danger has passed.
General growing tips
Start from seed, cuttings, or divisions. Plant in well-drained, lean soil. Prune lightly after flowering. Replace plants every 3-4 years when they become woody.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Thyme in Other Locations
Frequently Asked Questions
When should I plant Thyme in Clark County, WA?
Clark County is in Zone 8b with an average last frost of April 14. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clark County, WA?
Clark County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 27.
Your Clark County Garden Planner — Free
A 24-page printable planner built for Clark 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.