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When to plant Anemones in Summit County, CO

Summit County sits in cold Zone 5a. Plant Anemones June 16–June 30 for the single annual harvest; the September 4 first frost closes the window.

When to Plant Anemones in Summit County, CO

Summit County, Colorado Zone 5a June

Your June game plan for Summit County, Colorado

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Summit County, Colorado.

Avg. last frost June 16
Avg. first frost September 4
Soil temp (4") 45°F
Watering High
Pest pressure High
Daylight 14.8 hrs
  1. Plant out anemones

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

A few tasks this June that'll pay off in July
  • Starting indoors: anemones
  • First harvests: anemones

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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.

Summit County, Colorado is in USDA Zone 5a. 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 7,005 feet, Summit County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Anemones to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Anemones successfully. Mulch heavily to conserve soil moisture.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Summit County, CO (Zone 5a) Very short season
80 days
Last Spring Frost June 16
80 growing days
First Fall Frost September 4

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Anemones Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: May 13 Transplant: Jun 10 🌸 Bloom: Jul 22 – Aug 19
Recommended (50%) ✓ Fits season (10 days to spare)
Start indoors: May 19 Transplant: Jun 16 🌸 Bloom: Jul 28 – Aug 25
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: May 29 Transplant: Jun 26 🌸 Bloom: Aug 7 – Sep 4

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 Summit County

How your county's soil matches Anemones's growing requirements.

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Anemones prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Summit 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 (2.1%). Annual compost additions will help Anemones.

How to Plant Anemones

3"
Planting Depth
5"
Between Plants
6"
Between Rows

Anemones Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 326 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.8" 0" ❄️ Dormant
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Summit 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 needs ~1,129 GDD — county provides 860 GDD May not mature

Anemones Planting Timeline — Summit County, CO

Anemones Planting Calendar

Activity When Date Range
Start Indoors May 19 May 19 – Jun 2
Transplant Outdoors June 16 Jun 16 – Jun 30
Bloom July 28 Jul 28 – Aug 25

Plant 3" deep · 5" apart · Rows 6" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Start Indoors
June Start Indoors Transplant Outdoors
July Bloom
August Bloom
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

80 days in Summit County

Growing Tips for Anemones in Summit County

Direct sow Anemones outdoors after June 16 in Summit County when soil has warmed and frost danger has passed.

Your 80.0-day growing season in Summit County is tight for Anemones (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Summit County receives only 18" 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 →

Frequently Asked Questions

When should I plant Anemones in Summit County, CO?

Summit County is in Zone 5a with an average last frost of June 16. Plan your Anemones planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, CO?

Summit County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 4.

When should I plant Anemones in Summit County, CO?

In Summit County, CO, plant Anemones after the last frost (around June 16) and before the first frost (around September 4). Best results when soil holds above 50°F.

What growing zone is Summit County, CO for Anemones?

Summit County sits in USDA Zone 5a. Anemones grows reliably in zones 5a through 10b, so it's a good fit here.

Can Anemones grow in Summit County's climate?

Yes — Anemones grows well in Summit County's temperate climate. Summit County averages a 80-day frost-free season, with last frost around June 16 and first frost around September 4.

🌱

Your Summit County Garden Planner — Free

A 22-page printable planner built for Summit 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Summit County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.