When to plant Lilies in Pitkin County, CO
Pitkin County sits in cold Zone 5a. Plant Lilies June 30–July 14 for the single annual harvest; the September 7 first frost closes the window.
When to Plant Lilies in Pitkin County, CO
Lilies (Lilium spp.) are among the most impressive summer-blooming bulbs, delivering bold, upward- or outward-facing trumpet blooms on tall stems from June through August. Asiatic hybrids are the most cold-hardy, earliest to bloom, and easiest to grow; Oriental hybrids bloom later with intensely fragrant, larger flowers. Orienpet (OT) hybrids combine the hardiness of Asiatics with the fragrance and size of Orientals. True lilies (not to be confused with daylilies, which are Hemerocallis) form scaly bulbs that persist and multiply underground, returning reliably each year with increasingly large clumps.
Pitkin County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.
At an elevation of 6,411 feet, Pitkin County receives approximately 17.8 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Lilies to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Lilies successfully. Mulch heavily to conserve soil moisture.
Pitkin County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Lilies Planting Timeline — Pitkin County, CO
Lilies Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 30 | Jun 30 – Jul 14 |
| Bloom | September 8 | Sep 8 – Dec 1 |
Plant 5" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | — |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | Bloom |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–120 days
🧪 Soil pH
Needs 6–6.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5a
📆 Growing Season
83 days in Pitkin County
Growing Tips for Pitkin County
Plant bulbs in fall (preferred, September–October) or spring, setting them 3 times their diameter deep (typically 4–6 inches) with the pointed end up. Lilies need excellent drainage — they will rot in wet or heavy clay soils. Site with full sun on stems and blooms but cool, shaded soil at the base (ground cover or shallow-rooted annuals at their feet is ideal). Remove spent blooms but leave stems and foliage until they yellow naturally, as the bulb needs the foliage to photosynthesize and rebuild energy stores. Red lily beetle is a serious pest in the Northeast and Pacific Northwest; inspect plants regularly and hand-pick adults and larvae. Never plant Oriental or Asiatic lilies near cats — all Lilium species are highly toxic to cats. Year 2+ bulbs produce the most stems and largest blooms.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lilies in Other Locations
Frequently Asked Questions
When should I plant Lilies in Pitkin County, CO?
Pitkin County is in Zone 5a with an average last frost of June 16. Plan your Lilies planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pitkin County, CO?
Pitkin County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 7.
When should I plant Lilies in Pitkin County, CO?
In Pitkin County, CO, plant Lilies after the last frost (around June 16) and before the first frost (around September 7). Best results when soil holds above 50°F.
What growing zone is Pitkin County, CO for Lilies?
Pitkin County sits in USDA Zone 5a. Lilies grows reliably in zones 3a through 9a, so it's a good fit here.
Can Lilies grow in Pitkin County's climate?
Yes — Lilies grows well in Pitkin County's temperate climate. Pitkin County averages a 83-day frost-free season, with last frost around June 16 and first frost around September 7.
Your Pitkin County Garden Planner — Free
A 22-page printable planner built for Pitkin County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.