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When to Plant Strawberries in Washington County, OR

Washington County, Oregon Zone 8b May

Your May gardening checklist

Each item below is timed to Washington County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 15
Avg. first frost October 27
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs
  1. Get strawberries in the ground

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

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Strawberries are a beloved perennial fruit available as June-bearing, ever-bearing, and day-neutral types. They are one of the easiest fruits to grow in containers or garden beds.

Washington County, Oregon is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 27, giving you a growing season of approximately 195 days.

At an elevation of 352 feet, Washington County receives approximately 47.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Strawberries during the growing season.

Washington County, OR (Zone 8b) Moderate season
195 days
Last Spring Frost April 15
195 growing days
First Fall Frost October 27

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (278 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 29 – Jan 13
Recommended (50%) ✓ Fits season (280 days to spare)
Transplant: May 6 🍅 Harvest: Aug 5 – Jan 20
Safe Start (90%) ✓ Fits season (281 days to spare)
Transplant: May 29 🍅 Harvest: Aug 28 – Feb 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 Washington County

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

Soil pH

Your soil pH (5.8–6.4) is within Strawberries's preferred range (5.5–6.8).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Strawberries will thrive.

How to Plant Strawberries

12"
Between Plants
24"
Between Rows

How Much Strawberries to Grow

1 lb
Average yield per plant
10
Plants per person
20 sq ft
Space per person

For a family of 4, plant approximately 40 strawberries plants in about 80 sq ft. In Washington County's 195-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Strawberries

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

Month Strawberries Needs Rainfall You Supplement Action
Jan 7.4" 0" ❄️ Dormant
Feb 5.7" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 7.3" 0" ❄️ Dormant
Dec 8" 0" ❄️ Dormant

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

Strawberries 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.

Strawberries needs ~3,128 GDD — county provides 2,681 GDD May not mature

Strawberries Planting Timeline — Washington County, OR

Strawberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20
Harvest August 5 Aug 5 – Jan 20

· 12" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Harvest
February
March
April
May Transplant Outdoors
June
July
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–365 days

🧪 Soil pH

Needs 5.5–6.8 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

195 days in Washington County

Growing Tips for Strawberries in Washington County

Direct sow Strawberries outdoors after April 15 in Washington County when soil has warmed and frost danger has passed.

Your 195.0-day growing season in Washington County is tight for Strawberries (90.0-365.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant with crowns at soil level. Remove runners the first year to strengthen plants. Mulch with straw to keep fruit clean and suppress weeds. Renovate June-bearing beds after harvest.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Broccoli

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Strawberries in Washington County, OR?

Washington County is in Zone 8b with an average last frost of April 15. Plan your Strawberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, OR?

Washington County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 27.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington 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.

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 Washington County, OR. Local conditions may vary. Last updated: May 2026.

Sources & credits

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