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When to Plant Boysenberries in Ferry County, WA

Ferry County, Washington Zone 6b May

This month in Ferry County, Washington

Your garden in Ferry County, Washington is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 10
Avg. first frost September 24
Soil temp (4") 48°F
Watering Critical
Pest pressure Low
Daylight 15 hrs
  1. Move boysenberries into the garden

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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Boysenberries are a cross between raspberries, blackberries, and loganberries, producing large, dark, intensely flavored berries. They are excellent for jams and pies.

Ferry County, Washington is in USDA Zone 6b. The average last spring frost is May 10 and the first fall frost is September 24, giving you a growing season of approximately 137 days.

At an elevation of 3,990 feet, Ferry County receives approximately 18.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Boysenberries to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Boysenberries successfully. Mulch heavily to conserve soil moisture.

Ferry County, WA (Zone 6b) Short season
137 days
Last Spring Frost May 10
137 growing days
First Fall Frost September 24
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Ferry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 23
Recommended (50%) ✓ Fits season
Transplant: May 31
Safe Start (90%) ✓ Fits season
Transplant: Jun 19

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 Ferry County

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

Soil pH

Your soil pH (5.6–6.4) is within Boysenberries's preferred range (5.5–7.0).

Soil Texture

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

Drainage

Drainage is adequate for Boysenberries.

Organic Matter

Organic matter is excellent (4.6%) — Boysenberries will thrive.

How to Plant Boysenberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 905 gal / 100 sq ft

Monthly Watering Guide for Boysenberries

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

Month Boysenberries Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 4.3" 1.2" 3.1" 🚿 Regular watering
Jun 4.3" 0.7" 3.6" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.7" 3.6" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 2.5" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

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

Boysenberries 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.

Boysenberries needs ~7,118 GDD — county provides 1,781 GDD May not mature

Boysenberries Planting Timeline — Ferry County, WA

Boysenberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 31 May 31 – Jun 14

· 24" apart · Rows 72" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

137 days in Ferry County

Growing Tips for Boysenberries in Ferry County

Direct sow Boysenberries outdoors after May 10 in Ferry County when soil has warmed and frost danger has passed.

Your 137.0-day growing season in Ferry County is tight for Boysenberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Ferry County receives only 18" of rain annually. Boysenberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Provide strong trellising for vigorous canes. Prune spent canes to ground after harvest. Mulch heavily to retain moisture. Protect from wind to prevent cane damage.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Boysenberries in Ferry County, WA?

Ferry County is in Zone 6b with an average last frost of May 10. Plan your Boysenberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ferry County, WA?

Ferry County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 10 and first fall frost is September 24.

🌱

Your Ferry County Garden Planner — Free

A 24-page printable planner built for Ferry County (Zone 6b). 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 Ferry 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.