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When to Plant Impatiens in Wasco County, OR

Wasco County, Oregon Zone 7a June

This month in Wasco County, Oregon

Here's what deserves your attention in Wasco County, Oregon this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 23
Avg. first frost October 12
Soil temp (4") 74°F
Watering High
Pest pressure High
Daylight 15.4 hrs
  1. Get impatiens seeds going inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Looking ahead to July
  • First harvests: impatiens

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Impatiens (Impatiens walleriana) are the go-to annual for shaded beds and containers. They produce a continuous carpet of flat-faced blooms from transplant until frost, needing little deadheading. Their preference for consistent moisture and part-shade makes them ideal under trees and along north-facing borders.

Wasco County, Oregon is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.

At an elevation of 432 feet, Wasco County receives approximately 35.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Impatiens to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly
Wasco County, OR (Zone 7a) Moderate season
172 days
Last Spring Frost April 23
172 growing days
First Fall Frost October 12

Wasco County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 17 Transplant: Apr 21 🌸 Bloom: Jun 30 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Feb 26 Transplant: Apr 30 🌸 Bloom: Jul 9 – Oct 29
Safe Start (90%) ✗ May not fit
Start indoors: Mar 18 Transplant: May 20 🌸 Bloom: Jul 29 – Nov 18

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 Wasco County

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

Soil pH

Your soil pH (5.2–6.3) is more acidic than Impatiens prefers (6.0–6.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.2%) — Impatiens will thrive.

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

3
successive plantings in your 172-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 204 gal / 100 sq ft

Monthly Watering Guide for Impatiens

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

Month Impatiens Needs Rainfall You Supplement Action
Jan 4.3" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4" 0" ❄️ Dormant
Apr 4.3" 2.6" 1.7" 💧 Light watering
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.7" 3.6" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 5.1" 0" ❄️ Dormant
Dec 5.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Wasco County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Impatiens 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.

Impatiens needs ~675 GDD — county provides 1,720 GDD Excellent fit

Impatiens Planting Timeline — Wasco County, OR

Impatiens Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors April 30 Apr 30 – May 14
Bloom July 9 Jul 9 – Oct 29

· 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

172 days in Wasco County

Growing Tips for Impatiens in Wasco County

Direct sow Impatiens outdoors after April 23 in Wasco County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 8–10 weeks before last frost at 70–75°F; germination requires light — do not cover seeds. Transplant after last frost once nights consistently exceed 50°F. Water regularly — wilting causes bud drop and they rarely fully recover the same flush. Watch for impatiens downy mildew (IDM); consider New Guinea impatiens as a resistant alternative in affected regions. Pinch tips at planting to encourage branching.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Impatiens in Wasco County, OR?

Wasco County is in Zone 7a with an average last frost of April 23. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wasco County, OR?

Wasco County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 12.

🌱

Your Wasco County Garden Planner — Free

A 22-page printable planner built for Wasco County (Zone 7a). 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 Wasco 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.