Blog

When to Plant Mulberries in Skamania County, WA

Mulberries are fast-growing, long-lived trees that produce abundant sweet-tart berries over an extended harvest period. The berries resemble elongated blackberries.

Skamania County, Washington is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 19, giving you a growing season of approximately 184 days.

At an elevation of 16 feet, Skamania County receives approximately 43 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79ยฐF, so choose short-season varieties of Mulberries to ensure they mature before fall.

Skamania County, WA (Zone 7a) Moderate season
184 days
Last Spring Frost April 18
184 growing days
First Fall Frost October 19

Skamania County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 3
Recommended (50%) ✓ Fits season
Transplant: May 9
Safe Start (90%) ✓ Fits season
Transplant: May 31

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 Skamania County

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

Soil pH

Your soil pH (5.6โ€“6.2) is within Mulberries's preferred range (5.5โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) โ€” Mulberries will thrive.

How to Plant Mulberries

120"
Between Plants
144"
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 30 gal / 100 sq ft

Monthly Watering Guide for Mulberries

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

Month Mulberries Needs Rainfall You Supplement Action
Jan โ€” 6.5" 0" โ„๏ธ Dormant
Feb โ€” 4.3" 0" โ„๏ธ Dormant
Mar โ€” 3.8" 0" โ„๏ธ Dormant
Apr 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
May 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Jun 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Jul 4.3" 0.7" 3.6" ๐Ÿšฟ Regular watering
Aug 4.3" 0.7" 3.6" ๐Ÿšฟ Regular watering
Sep 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Oct 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Nov โ€” 7.4" 0" โ„๏ธ Dormant
Dec โ€” 7.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Skamania County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Mulberries 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.

Mulberries needs ~11,817 GDD — county provides 1,702 GDD May not mature

Mulberries Planting Timeline โ€” Skamania County, WA

Mulberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 9 May 9 โ€“ May 23

ยท 120" apart ยท Rows 144" 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 Only during dry spells

๐Ÿ“… Days to Maturity

730โ€“1825 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

184 days in Skamania County

Growing Tips for Mulberries in Skamania County

Direct sow Mulberries outdoors after April 18 in Skamania County when soil has warmed and frost danger has passed.

Your 184.0-day growing season in Skamania County is tight for Mulberries (730.0-1825.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant away from driveways and patios as fallen berries stain. Minimal pruning is needed. Harvest by shaking branches over a tarp. Birds love mulberries so plant extra.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mulberries in Skamania County, WA?

Skamania County is in Zone 7a with an average last frost of April 18. Plan your Mulberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Skamania County, WA?

Skamania County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Skamania County gardeners in Zone 7a 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 Skamania County, WA. Local conditions may vary. Last updated: April 2026.