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When to Plant Roses in Walla Walla County, WA

Walla Walla County, Washington Zone 7a June

June in Walla Walla County, Washington — your action list

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

Avg. last frost April 20
Avg. first frost October 15
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 15.6 hrs
  1. Start roses under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Get ahead of July
  • First harvests: roses

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Roses (Rosa spp.) are the world's most beloved flowering shrubs, grown for centuries for their exquisite blooms, fragrance, and versatility. Modern repeat-blooming cultivars deliver continuous color from late spring through the first hard frost, while old garden roses typically offer a single magnificent spring flush. Hardy shrub roses such as the Knock Out® and Canadian Explorer series tolerate Zone 3–4 winters without protection. With correct siting (6+ hours of sun, good air circulation), disease- resistant varieties thrive with moderate maintenance.

Walla Walla County, Washington is in USDA Zone 7a. The average last spring frost is April 20 and the first fall frost is October 15, giving you a growing season of approximately 178 days.

At an elevation of 3,151 feet, Walla Walla County receives approximately 23.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Roses during the growing season.

Perennial Blooms in Multi-season Pollinator-friendly Good for cutting Fragrant
Walla Walla County, WA (Zone 7a) Moderate season
178 days
Last Spring Frost April 20
178 growing days
First Fall Frost October 15

Walla Walla County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Roses Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Jan 23 Transplant: Apr 10 🌸 Bloom: Jun 19 – Oct 23
Recommended (50%) ✗ May not fit
Start indoors: Feb 9 Transplant: Apr 27 🌸 Bloom: Jul 6 – Nov 9
Safe Start (90%) ✗ May not fit
Start indoors: Mar 5 Transplant: May 21 🌸 Bloom: Jul 30 – Dec 3

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 Walla Walla County

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

Soil pH

Your soil pH (5.2–6.4) is more acidic than Roses prefers (6.0–6.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Roses will thrive.

How to Plant Roses

1"
Planting Depth
36"
Between Plants
48"
Between Rows

Roses Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 702 gal / 100 sq ft

Monthly Watering Guide for Roses

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

Month Roses Needs Rainfall You Supplement Action
Jan 2.9" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.5" 3.8" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 4.3" 2.2" 2.1" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

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

Roses 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.

Roses needs ~1,856 GDD — county provides 2,447 GDD Excellent fit

Roses Planting Timeline — Walla Walla County, WA

Roses Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 – Feb 23
Transplant Outdoors April 27 Apr 27 – May 11
Bloom July 6 Jul 6 – Nov 9

Plant 1" deep · 36" apart · Rows 48" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–180 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

178 days in Walla Walla County

Growing Tips for Roses in Walla Walla County

Direct sow Roses outdoors after April 20 in Walla Walla County when soil has warmed and frost danger has passed.

Your 178.0-day growing season in Walla Walla County is tight for Roses (90.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

Walla Walla County receives only 24" of rain annually. Roses needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant bare-root roses in early spring as soon as soil is workable, or set container-grown plants from spring through early fall. Dig a wide, deep hole; amend with compost and a handful of bone meal. Set the graft union 1–2 inches below soil level in Zones 3–6 for winter protection, at soil level in Zones 7+. Water deeply twice weekly until established. Fertilize with a balanced rose food every 4–6 weeks during the growing season. Prune hybrid teas and grandifloras to outward-facing buds in early spring when forsythia blooms. Deadhead to encourage repeat bloom. Fall planting (Zones 5+) can improve establishment in subsequent years. Year 2+ plants deliver the fullest bloom display.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Brassicas

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Roses in Walla Walla County, WA?

Walla Walla County is in Zone 7a with an average last frost of April 20. Plan your Roses planting based on this frost date — see the calendar above for exact timing.

What planting zone is Walla Walla County, WA?

Walla Walla County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 20 and first fall frost is October 15.

🌱

Your Walla Walla County Garden Planner — Free

A 22-page printable planner built for Walla Walla 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 Walla Walla County, WA. 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.