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When to Plant Raspberries in Snohomish County, WA

Snohomish County, Washington Zone 8b May

Your May gardening checklist

A quick May briefing for Snohomish County, Washington gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 25
Avg. first frost November 2
Soil temp (4") 70°F
Watering High
Pest pressure High
Daylight 15 hrs

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Raspberries are beloved bramble fruits producing sweet, delicate berries in red, golden, black, and purple varieties. They spread by underground runners and are very productive.

Snohomish County, Washington is in USDA Zone 8b. The average last spring frost is March 25 and the first fall frost is November 2, giving you a growing season of approximately 222 days.

At an elevation of 230 feet, Snohomish County receives approximately 50.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Raspberries during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Raspberries root diseases.

Snohomish County, WA (Zone 8b) Long season
222 days
Last Spring Frost March 25
222 growing days
First Fall Frost November 2
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Snohomish County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 9
Recommended (50%) ✓ Fits season
Transplant: Apr 15
Safe Start (90%) ✓ Fits season
Transplant: May 9

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 Snohomish County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Raspberries's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) — Raspberries will thrive.

How to Plant Raspberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 84 gal / 100 sq ft

Monthly Watering Guide for Raspberries

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

Month Raspberries Needs Rainfall You Supplement Action
Jan 7.7" 0" ❄️ Dormant
Feb 5.6" 0" ❄️ Dormant
Mar 4.3" 5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 0.7" 3.6" 🚿 Regular watering
Aug 4.3" 1" 3.3" 🚿 Regular watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 4.3" 8" 0" ✅ Rainfall sufficient
Dec 8.5" 0" ❄️ Dormant

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

Raspberries 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.

Raspberries needs ~9,581 GDD — county provides 3,885 GDD May not mature

Raspberries Planting Timeline — Snohomish County, WA

Raspberries Planting Calendar

Activity When Date Range
Transplant Outdoors April 15 Apr 15 – Apr 29

· 24" apart · Rows 72" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

222 days in Snohomish County

Growing Tips for Raspberries in Snohomish County

Direct sow Raspberries outdoors after March 25 in Snohomish County when soil has warmed and frost danger has passed.

Your 222.0-day growing season in Snohomish County is tight for Raspberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Provide a trellis for support. Prune summer-bearing types by removing spent canes after harvest. For ever-bearing types, mow all canes in late winter for a single fall crop.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Raspberries in Snohomish County, WA?

Snohomish County is in Zone 8b with an average last frost of March 25. Plan your Raspberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Snohomish County, WA?

Snohomish County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is March 25 and first fall frost is November 2.

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Your Snohomish County Garden Planner — Free

A 24-page printable planner built for Snohomish 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 Snohomish County, WA. 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.