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When to plant Pansy in Summit County County,

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

When to Plant Pansy in Summit County, CO

Summit County, Colorado Zone 5a June

Top priorities for Summit County, Colorado gardeners in June

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 pansy

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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Pansies (Viola × wittrockiana) are beloved cool-season annuals offering some of the widest color range in the annual garden. Their cheerful "faces" appear in early spring — or even late winter in mild climates — and hold up remarkably well through frosts. Heat causes them to go leggy and stop blooming; replace with warm-season annuals once daytime temps exceed 70°F.

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 Pansy to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Pansy successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Spring Pollinator-friendly 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

Pansy Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: Jun 10 🌸 Bloom: Aug 5 – Sep 30
Recommended (50%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 16 🌸 Bloom: Aug 11 – Oct 6
Safe Start (90%) ✗ May not fit
Start indoors: Apr 17 Transplant: Jun 26 🌸 Bloom: Aug 21 – Oct 16

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 Pansy's growing requirements.

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Pansy prefers (5.4–6.2). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Summit County is excellent for Pansy — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Pansy.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Pansy.

How to Plant Pansy

0.3"
Planting Depth
7"
Between Plants
10"
Between Rows

Pansy 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 Pansy

Pansy needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Pansy 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.

Pansy 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.

Pansy needs ~860 GDD — county provides 860 GDD Tight fit

Pansy Planting Timeline — Summit County, CO

Pansy Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors June 16 Jun 16 – Jun 30
Bloom August 11 Aug 11 – Oct 6

Plant 0.3" deep · 7" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.4–6.2 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

80 days in Summit County

Growing Tips for Pansy in Summit County

Direct sow Pansy 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 Pansy (70.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

Summit County receives only 18" of rain annually. Pansy needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start indoors 10-12 weeks before last frost for spring transplants. In zones 6+, fall planting (8-10 weeks before first frost) gives overwintering plants that bloom earliest in spring. Plant in full sun in cool weather; afternoon shade helps extend bloom in zones 7-8. Deadhead to prevent premature seed set. Shear back by one-third when plants go leggy to extend the season.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pansy in Summit County, CO?

Summit County is in Zone 5a with an average last frost of June 16. Plan your Pansy 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 Pansy in Summit County County, ?

In Summit County County, , plant Pansy 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 County, for Pansy?

Summit County County sits in USDA Zone 5a. Pansy grows reliably in zones 3a through 10b, so it's a good fit here.

Can Pansy grow in Summit County County's climate?

Yes — Pansy grows well in Summit County County's temperate climate. Summit County 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.