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When to Plant Elderberries in Asotin County, WA

Elderberries are fast-growing shrubs or small trees producing clusters of small, dark berries used for syrups, wines, and immune-boosting preparations. The flowers are also edible.

Asotin County, Washington is in USDA Zone 6b. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.

At an elevation of 2,029 feet, Asotin County receives approximately 14 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Elderberries during the growing season. With low rainfall, drip irrigation is essential for growing Elderberries successfully. Mulch heavily to conserve soil moisture.

Asotin County, WA (Zone 6b) Short season
144 days
Last Spring Frost May 9
144 growing days
First Fall Frost September 30

Asotin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 19
Recommended (50%) ✓ Fits season
Transplant: May 30
Safe Start (90%) ✓ Fits season
Transplant: Jun 27

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 Asotin County

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

Soil pH

Your soil pH (5.5โ€“6.5) is within Elderberries's preferred range (5.5โ€“6.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) โ€” Elderberries will thrive.

How to Plant Elderberries

120"
Between Plants
144"
Between Rows

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.4″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 502 gal / 100 sq ft

Monthly Watering Guide for Elderberries

Elderberries needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Elderberries Needs Rainfall You Supplement Action
Jan โ€” 2" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 0.9" 0" โ„๏ธ Dormant
May 3.5" 0.8" 2.7" ๐Ÿšฟ Regular watering
Jun 3.5" 0.6" 2.9" ๐Ÿšฟ Regular watering
Jul 3.5" 0.2" 3.3" ๐Ÿšฟ Regular watering
Aug 3.5" 0.3" 3.2" ๐Ÿšฟ Regular watering
Sep 3.5" 0.5" 3" ๐Ÿšฟ Regular watering
Oct โ€” 1.2" 0" โ„๏ธ Dormant
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

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

Elderberries 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.

Elderberries needs ~12,547 GDD — county provides 1,980 GDD May not mature

Elderberries Planting Timeline โ€” Asotin County, WA

Elderberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 30 May 30 โ€“ Jun 13

ยท 120" apart ยท Rows 144" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June Transplant Outdoors
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

0.8"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

730โ€“1095 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

144 days in Asotin County

Growing Tips for Elderberries in Asotin County

Direct sow Elderberries outdoors after May 09 in Asotin County when soil has warmed and frost danger has passed.

Your 144.0-day growing season in Asotin County is tight for Elderberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant at least two varieties for cross-pollination. Prune annually to remove old canes and maintain shape. Berries must be cooked before eating as raw berries are mildly toxic.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Elderberries in Asotin County, WA?

Asotin County is in Zone 6b with an average last frost of May 9. Plan your Elderberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Asotin County, WA?

Asotin County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 9 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Asotin County gardeners in Zone 6b 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 Asotin County, WA. Local conditions may vary. Last updated: April 2026.