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When to Plant Boysenberries in Clatsop County, OR

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

Clatsop County, Oregon is in USDA Zone 8b. The average last spring frost is April 12 and the first fall frost is November 4, giving you a growing season of approximately 206 days.

At an elevation of 412 feet, Clatsop County receives approximately 54.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Boysenberries during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Boysenberries root diseases.

Clatsop County, OR (Zone 8b) Long season
206 days
Last Spring Frost April 12
206 growing days
First Fall Frost November 4

Clatsop County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 22
Recommended (50%) ✓ Fits season
Transplant: May 3
Safe Start (90%) ✓ Fits season
Transplant: May 21

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 Clatsop County

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

Soil pH

Your soil pH (5.6โ€“6.7) is within Boysenberries's preferred range (5.5โ€“7.0).

Soil Texture

The silt loam soil in Clatsop County is excellent for Boysenberries โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.9%) โ€” Boysenberries will thrive.

How to Plant Boysenberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 8.4" 0" โ„๏ธ Dormant
Feb โ€” 5.2" 0" โ„๏ธ Dormant
Mar โ€” 4.8" 0" โ„๏ธ Dormant
Apr 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
May 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jun 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Aug 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Sep 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Oct 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Nov 4.3" 8.4" 0" โœ… Rainfall sufficient
Dec โ€” 9.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Clatsop County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~7,939 GDD — county provides 2,987 GDD May not mature

Boysenberries Planting Timeline โ€” Clatsop County, OR

Boysenberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 3 May 3 โ€“ May 17

ยท 24" apart ยท Rows 72" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

365โ€“730 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

206 days in Clatsop County

Growing Tips for Boysenberries in Clatsop County

Direct sow Boysenberries outdoors after April 12 in Clatsop County when soil has warmed and frost danger has passed.

Your 206.0-day growing season in Clatsop County is tight for Boysenberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Clatsop County, OR?

Clatsop County is in Zone 8b with an average last frost of April 12. Plan your Boysenberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clatsop County, OR?

Clatsop County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 12 and first fall frost is November 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clatsop County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clatsop County, OR. Local conditions may vary. Last updated: April 2026.