When to plant Anemones in Boulder County, CO
Boulder County sits in cold Zone 6a. Plant Anemones May 14–May 28 for the single annual harvest; the September 26 first frost closes the window.
When to Plant Anemones in Boulder County, CO
What to do in June
Each item below is timed to Boulder County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Time to start anemones inside
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
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Basket week: anemones
If you can't use it all right away, check the food-preservation section of your planner.
Before July arrives, get these ready
- First harvests: anemones
Poppy anemones (Anemone coronaria) produce vivid, poppy-like flowers with striking black centers, in shades of red, blue, purple, white, and bicolor. A cool-season cut flower favorite, they thrive in the mild overlap between winter's end and summer's arrival. In mild-winter zones (7+), fall planting yields a spectacular mid-spring bloom flush that florists prize. In colder zones, spring planting produces summer flowers. The 'Meron' and 'Moissonnier' series dominate commercial cut flower production; 'De Caen' and 'St. Brigid' are standard home garden strains.
Boulder County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.
At an elevation of 7,657 feet, Boulder County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Anemones during the growing season.
Boulder County Soil Profile
Soil Type
Loam
Soil pH
6.7-8
Drainage
Well Drained
Anemones 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 Boulder County
How your county's soil matches Anemones's growing requirements.
Soil pH
Your soil pH (6.7–8.0) is more alkaline than Anemones prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Boulder County is excellent for Anemones — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Anemones.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Anemones.
How to Plant Anemones
Anemones Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Anemones
Anemones needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Anemones Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 4.3" | 3" | 1.3" | 💧 Light watering |
| Jun | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Jul | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Aug | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Sep | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Boulder County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Anemones Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Anemones Planting Timeline — Boulder County, CO
Anemones Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 16 | Apr 16 – Apr 30 |
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Bloom | June 18 | Jun 18 – Jul 16 |
Plant 3" deep · 5" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors |
| June | Bloom |
| July | Bloom |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
135 days in Boulder County
Growing Tips for Anemones in Boulder County
Direct sow Anemones outdoors after May 14 in Boulder County when soil has warmed and frost danger has passed.
Boulder County receives only 22" of rain annually. Anemones needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Soak corms in tepid water for 2–4 hours before planting to rehydrate them. Plant 2–3 inches deep with the flat or rough side down (corms are irregular). Space 4–6 inches apart. Anemones are cool-season plants — they need cool temperatures to set buds; summer heat causes dormancy. In zones 7+, fall planting allows corms to root through winter and bloom in March–April. In zones 5–6, start corms indoors 4 weeks before last frost, then transplant after danger of hard freeze passes. In zones 9–10b, plant from October through January for a succession of blooms. After bloom, allow foliage to die back; corms can be lifted, dried, and stored in a cool, dry place through summer.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Anemones in Other Locations
Frequently Asked Questions
When should I plant Anemones in Boulder County, CO?
Boulder County is in Zone 6a with an average last frost of May 14. Plan your Anemones planting based on this frost date — see the calendar above for exact timing.
What planting zone is Boulder County, CO?
Boulder County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.
When should I plant Anemones in Boulder County, CO?
In Boulder County, CO, plant Anemones after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.
What growing zone is Boulder County, CO for Anemones?
Boulder County sits in USDA Zone 6a. Anemones grows reliably in zones 5a through 10b, so it's a good fit here.
Can Anemones grow in Boulder County's climate?
Yes — Anemones grows well in Boulder County's temperate climate. Boulder County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.
Your Boulder County Garden Planner — Free
A 22-page printable planner built for Boulder County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.