When to Plant Yarrow in Park County, CO
Yarrow is a drought-tolerant perennial herb with feathery foliage and flat-topped flower clusters in white, yellow, pink, or red. It attracts beneficial insects and is used in herbal medicine.
Park County, Colorado is in USDA Zone 4b. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.
At an elevation of 7,567 feet, Park County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Yarrow to ensure they mature before fall.
Park County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.6
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Yarrow Planting Timeline — Park County, CO
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 23 | Jun 23 – Jul 7 |
| Harvest | September 22 | Sep 22 – Nov 17 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | — |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
90–120 days
Soil pH
5.5 – 7
USDA Zone
Zone 4b
Growing Season
80 days
Growing Tips for Park County
Direct sow or start from divisions. Yarrow thrives in poor soil and is very drought-tolerant. Deadhead to encourage reblooming. Divide clumps every 3 years.
Companion Planting
Good Companions
Level Up Your Garden
Yarrow in Other Locations
Frequently Asked Questions
When should I plant Yarrow in Park County, CO?
Park County is in Zone 4b with an average last frost of June 16. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is Park County, CO?
Park County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 16 and first fall frost is September 4.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Park County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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