Western Serviceberry

Amelanchier alnifolia

Rosaceae · broadleaf deciduous shrub · native

Last updated

Data Coverage 5 of 6 dimensions
Site Data
Threats
Cultivars
Phenology
GDD Thresholds
Puget Sound

Western serviceberry (also called Saskatoon berry) is a native multi-stemmed shrub-tree of dry to moist forest edges and woodland transitions across western North America, from Alaska to northern California and east to the Great Plains. The bark is smooth and gray. The leaves are oval, lightly toothed, and turn red to orange in fall. The flowers appear in upright racemes, and the small blue-black berries in early summer are highly valued by birds and wildlife. The tree rarely exceeds 20 to 25 feet and often remains more shrubby in drier sites.

Western serviceberry is a useful native for dry to moist sites with full sun to part shade and adaptable soil conditions. Growth is moderate, reaching mature size in 12 to 15 years. The tree is relatively pest and disease-free, making it a low-maintenance choice. The blue-black fruits ripen in June and are quickly consumed by birds; if you wish to harvest berries, use bird netting. Fall color is reliable, ranging from orange to red. For riparian restoration, understory planting, and wildlife corridors, western serviceberry offers multiple seasons of interest: spring flowers, summer fruits, fall color, and winter form.

Quick Facts

Height
20–30 ft
Spread
9 ft
Growth Rate
Moderate
Light
Full Sun
Soil
Adaptable
Water
Low
Hardiness
Zone Zones 2a–8b
Fall Color
Orange, purple, red, yellow
Origin
Pacific Northwest native

Phenological Calendar

As of April 21, 2026, Puget Sound stations range from 1393.7 to 1554.7 GDD₃₂. Western Serviceberry has passed 'first bloom' (1428 GDD₃₂).

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 21, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,555 'First bloom'
Seattle / UW 1,516 'First bloom'
Kent / Auburn 1,497 'First bloom'
Olympia / Tumwater 1,467 'First bloom'
Bellingham / Whatcom 1,440 'First bloom'
Tacoma / Puyallup 1,434 'First bloom'
Sequim / Rain Shadow 1,394 'Flower buds visible' 'First bloom' 34
Stage GDD32 Typical Window
'Bud break' BBCH '07' 886 ''
'Leaf emergence' BBCH '11' 1178 ''
'Flower buds visible' BBCH '51' 1215 ''
'First bloom' BBCH '61' NOW 1428 ''
Range: 550–706 GDD₃₂ (6yr)

GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? GDD₃₂ thresholds from USA National Phenology Network citizen science observations (WA+OR). Season tracker for Kent / Auburn as of Apr 21, 2026. Predicted dates use 16-day weather forecast through May 7, 2026, then climate normals.

Diseases (1)

Cultivars (1)

'Regent'
Common name: Regent Serviceberry Regent Saskatoon Berry; Mature height: 4–6 ft
Hardy to USDA Zone 2