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When to Plant Serviceberries in Napa County, CA

Serviceberries (saskatoons) are attractive native shrubs or small trees producing sweet, blueberry-like fruits. They have beautiful spring flowers and vibrant fall color.

Napa County, California is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 449 feet, Napa County receives approximately 35 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Serviceberries during the growing season.

Napa County, CA (Zone 9a) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Napa County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Feb 24
Recommended (50%) ✓ Fits season
Transplant: Mar 12
Safe Start (90%) ✓ Fits season
Transplant: Apr 16

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
0.5″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,234 gal / 100 sq ft
Drought risk

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

Serviceberries needs ~14,600 GDD — county provides 4,384 GDD May not mature

Serviceberries Planting Timeline โ€” Napa County, CA

Serviceberries Planting Calendar

Activity When Date Range
Transplant Outdoors March 12 Mar 12 โ€“ Mar 26

ยท 120" apart ยท Rows 144" apart

Month-by-Month Timeline

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

730โ€“1095 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 9a

Growing Season

273 days

Growing Tips for Napa County

Plant in well-drained soil. Minimal pruning needed beyond removing dead wood. Protect fruit from birds with netting. Berries ripen in early summer and are excellent fresh or in pies.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Serviceberries in Napa County, CA?

Napa County is in Zone 9a with an average last frost of February 26. Plan your Serviceberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Napa County, CA?

Napa County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Napa County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Napa County, CA. Local conditions may vary. Last updated: April 2026.