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When to Plant Pansy in Union County, OR

Union County, Oregon Zone 6b July

What to do in July

A quick July briefing for Union County, Oregon gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 12
Avg. first frost September 26
Soil temp (4") 70°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. Sow pansy in trays indoors

    These need a head start before your last frost (May 12). Sow into cells now so you're ready to transplant in a few weeks.

  2. Bring in the pansy

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

August will be here before you know it — start on
  • First harvests: pansy
  • Fall sowing: pansy

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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.

Union County, Oregon is in USDA Zone 6b. The average last spring frost is May 12 and the first fall frost is September 26, giving you a growing season of approximately 137 days.

At an elevation of 2,751 feet, Union County receives approximately 23.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Pansy during the growing season.

Annual Blooms in Spring Pollinator-friendly Good for cutting
Union County, OR (Zone 6b) Short season
137 days
Last Spring Frost May 12
137 growing days
First Fall Frost September 26

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Pansy Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Feb 22 Transplant: May 3 🌸 Bloom: Jun 28 – Sep 6
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 3 Transplant: May 12 🌸 Bloom: Jul 7 – Sep 15
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Mar 30 Transplant: Jun 8 🌸 Bloom: Aug 3 – Oct 12

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 Union County

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

Soil pH

Your soil pH (5.2–6.6) overlaps with Pansy's range (5.4–6.2), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Pansy.

Organic Matter

Organic matter is excellent (5.6%) — Pansy will thrive.

How to Plant Pansy

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Pansy

2
successive plantings in your 137-day season

Sow every 8 weeks. Last sowing by Jun 28 to harvest before frost.

For a dedicated fall crop, sow by Aug 01.

Pansy Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 707 gal / 100 sq ft

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 2.9" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.5" 3.8" 🚿 Regular watering
Sep 4.3" 1" 3.3" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 3.8" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Union 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 ~1,160 GDD — county provides 1,986 GDD Excellent fit

Pansy Planting Timeline — Union County, OR

Pansy Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors May 12 May 12 – May 26
Bloom July 7 Jul 7 – Sep 15
Fall Sowing August 1 Aug 1 – Aug 15

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors
June
July Bloom
August Fall Sowing Bloom
September Bloom
October
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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

137 days in Union County

Growing Tips for Pansy in Union County

Direct sow Pansy outdoors after May 12 in Union County when soil has warmed and frost danger has passed.

Union County receives only 24" 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 Union County, OR?

Union County is in Zone 6b with an average last frost of May 12. Plan your Pansy planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, OR?

Union County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is May 12 and first fall frost is September 26.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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