When to plant Peonies in Douglas County, CO
Douglas County sits in cold Zone 5b. Plant Peonies June 5–June 19 for the single annual harvest; the September 20 first frost closes the window.
When to Plant Peonies in Douglas County, CO
Peonies (Paeonia lactiflora) are the crown jewels of the spring garden — magnificent, fragrant blooms in white, pink, and red that can last 100 years or more in the same spot with minimal care. Extremely cold-hardy and requiring a period of winter chill to bloom, they are most productive in Zones 3–7. Each established clump produces dozens of lush, fully double or semi-double flowers over a 2–3 week window in late spring. Virtually pest-free beyond the cosmetic presence of ants on buds (which are harmless). Once sited correctly, peonies rarely need dividing or moving.
Douglas County, Colorado is in USDA Zone 5b. The average last spring frost is May 22 and the first fall frost is September 20, giving you a growing season of approximately 121 days.
At an elevation of 7,421 feet, Douglas County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Peonies during the growing season. With low rainfall, drip irrigation is essential for growing Peonies successfully. Mulch heavily to conserve soil moisture.
Douglas County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Peonies Planting Timeline — Douglas County, CO
Peonies Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 5 | Jun 5 – Jun 19 |
| Bloom | August 14 | Aug 14 – Sep 25 |
Plant 1.5" deep · 36" apart · Rows 48" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6.5–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
121 days in Douglas County
Growing Tips for Douglas County
Plant bare-root divisions in fall (late September through October in Zones 3–7; November in Zone 8) with eyes facing upward and positioned exactly 1–2 inches below soil surface — deeper planting is the most common reason peonies fail to bloom. Choose a site with full sun and excellent drainage. Peonies require 6+ weeks of temperatures below 40°F (cold stratification period) for reliable bloom — they do not perform well in Zone 9+. Do not expect full bloom the first or second year; Year 3+ plants deliver the most impressive flowering. Avoid moving established plants. Stake double- flowered types before heavy blooms cause stems to flop. Cut stems to ground in fall after frost kills foliage to prevent botrytis overwinter.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Peonies in Other Locations
Frequently Asked Questions
When should I plant Peonies in Douglas County, CO?
Douglas County is in Zone 5b with an average last frost of May 22. Plan your Peonies planting based on this frost date — see the calendar above for exact timing.
What planting zone is Douglas County, CO?
Douglas County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 22 and first fall frost is September 20.
When should I plant Peonies in Douglas County, CO?
In Douglas County, CO, plant Peonies after the last frost (around May 22) and before the first frost (around September 20). Best results when soil holds above 50°F.
What growing zone is Douglas County, CO for Peonies?
Douglas County sits in USDA Zone 5b. Peonies grows reliably in zones 3a through 8b, so it's a good fit here.
Can Peonies grow in Douglas County's climate?
Yes — Peonies grows well in Douglas County's temperate climate. Douglas County averages a 121-day frost-free season, with last frost around May 22 and first frost around September 20.
Your Douglas County Garden Planner — Free
A 22-page printable planner built for Douglas County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.