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When to Plant Boysenberries in Chelan County, WA

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

Chelan County, Washington is in USDA Zone 6a. The average last spring frost is April 24 and the first fall frost is October 20, giving you a growing season of approximately 179 days.

At an elevation of 3,517 feet, Chelan County receives approximately 14.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Boysenberries during the growing season. With low rainfall, drip irrigation is essential for growing Boysenberries successfully. Mulch heavily to conserve soil moisture.

Chelan County, WA (Zone 6a) Moderate season
179 days
Last Spring Frost April 24
179 growing days
First Fall Frost October 20

Chelan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 4
Recommended (50%) ✓ Fits season
Transplant: May 15
Safe Start (90%) ✓ Fits season
Transplant: Jun 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,275 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Boysenberries needs ~8,349 GDD — county provides 2,729 GDD May not mature

Boysenberries Planting Timeline โ€” Chelan County, WA

Boysenberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 15 May 15 โ€“ May 29

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

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

365โ€“730 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 6a

Growing Season

179 days

Growing Tips for Chelan County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Boysenberries in Chelan County, WA?

Chelan County is in Zone 6a with an average last frost of April 24. Plan your Boysenberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Chelan County, WA?

Chelan County, Washington is in USDA Hardiness Zone 6a. The average last spring frost is April 24 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Chelan County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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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 Chelan County, WA. Local conditions may vary. Last updated: April 2026.