When to Plant Thyme in Columbia County, WA
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.
Columbia County, Washington is in USDA Zone 6b. The average last spring frost is April 28 and the first fall frost is October 11, giving you a growing season of approximately 166 days.
At an elevation of 3,157 feet, Columbia County receives approximately 21.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Thyme during the growing season.
Columbia County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.5
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.
Plant Water Budget
Thyme Planting Timeline — Columbia County, WA
Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Harvest | July 14 | Jul 14 – Sep 15 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
70–90 days
Soil pH
6 – 8
USDA Zone
Zone 6b
Growing Season
166 days
Growing Tips for Columbia County
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
Level Up Your Garden
Thyme in Other Locations
Frequently Asked Questions
When should I plant Thyme in Columbia County, WA?
Columbia County is in Zone 6b with an average last frost of April 28. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.
What planting zone is Columbia County, WA?
Columbia County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is April 28 and first fall frost is October 11.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Columbia County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.