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When to Plant Pansy in Benton County, OR

Benton County, Oregon Zone 8b June

Your June planting checklist for Benton County, Oregon

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 14
Avg. first frost October 30
Soil temp (4") 80°F
Watering High
Pest pressure High
Daylight 15.3 hrs
  1. Indoor seed-starting week for pansy

    You're about 19 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. It's harvest week for pansy

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

To set up a strong July, finish these tasks
  • First harvests: 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.

Benton County, Oregon is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.

At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Pansy during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Pansy root diseases.

Annual Blooms in Spring Pollinator-friendly Good for cutting
Benton County, OR (Zone 8b) Moderate season
199 days
Last Spring Frost April 14
199 growing days
First Fall Frost October 30

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Pansy Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Jan 16 Transplant: Mar 6 🌸 Bloom: May 1 – Aug 21
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Feb 3 Transplant: Mar 24 🌸 Bloom: May 19 – Sep 8
Safe Start (90%) ✓ Fits season (59 days to spare)
Start indoors: Feb 26 Transplant: Apr 16 🌸 Bloom: Jun 11 – Oct 1

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 Benton County

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

Soil pH

Your soil pH (5.6–6.2) is within Pansy's preferred range (5.4–6.2).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Pansy will thrive.

How to Plant Pansy

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Pansy

3
successive plantings in your 199-day season

Sow every 8 weeks. Last sowing by Aug 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 21.

Pansy Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 8.1" 0" ❄️ Dormant
Feb 6.1" 0" ❄️ Dormant
Mar 5.8" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 0.9" 3.4" 🚿 Regular watering
Aug 4.3" 0.8" 3.5" 🚿 Regular watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 8.3" 0" ❄️ Dormant
Dec 8.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Benton 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 ~1,100 GDD — county provides 2,736 GDD Excellent fit

Pansy Planting Timeline — Benton County, OR

Pansy Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 – Feb 17
Transplant Outdoors March 24 Mar 24 – Apr 7
Bloom May 19 May 19 – Sep 8
Fall Sowing August 21 Aug 21 – Sep 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.4–6.2 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

199 days in Benton County

Growing Tips for Pansy in Benton County

Direct sow Pansy outdoors after April 14 in Benton County when soil has warmed and frost danger has passed.

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 Benton County, OR?

Benton County is in Zone 8b with an average last frost of April 14. Plan your Pansy planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benton County, OR?

Benton County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 30.

🌱

Your Benton County Garden Planner — Free

A 22-page printable planner built for Benton County (Zone 8b). 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 Benton County, OR. 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.