When to Plant Thyme in Custer County, CO
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.
Custer County, Colorado is in USDA Zone 5a. The average last spring frost is May 23 and the first fall frost is September 25, giving you a growing season of approximately 125 days.
At an elevation of 8,115 feet, Custer County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Thyme during the growing season. With low rainfall, drip irrigation is essential for growing Thyme successfully. Mulch heavily to conserve soil moisture.
Custer County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.8
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 Custer County
How your county's soil matches Thyme's growing requirements.
Soil pH
Your soil pH (6.5–7.8) is within Thyme's preferred range (6.0–8.0).
Soil Texture
The loam soil in Custer County is excellent for Thyme — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Thyme.
How to Plant Thyme
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Thyme Planting Timeline — Custer County, CO
Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 30 | May 30 – Jun 13 |
| Harvest | August 8 | Aug 8 – Oct 10 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| 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: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
125 days in Custer County
Growing Tips for Thyme in Custer County
Direct sow Thyme outdoors after May 23 in Custer 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
Level Up Your Garden
Thyme in Other Locations
Frequently Asked Questions
When should I plant Thyme in Custer County, CO?
Custer County is in Zone 5a with an average last frost of May 23. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.
What planting zone is Custer County, CO?
Custer County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 23 and first fall frost is September 25.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Custer County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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