Alder

Frangula alnus

Rhamnaceae · broadleaf deciduous shrub · introduced

Last updated March 9, 2026

Data Maturity Structured

This profile synthesizes data from multiple published sources. Expert field review is in progress.

Quick Facts

Height

15 ft

Spread

13 ft

Growth Rate

Fast

Light

Full Sun

Soil

Adaptable

Water

Moderate

Hardiness

Zone Zones 3a–8b

Bloom Time

Apr 1-Apr 30

Fall Color

Yellow

Origin

Europe, western Asia and North Africa

Stage	Typical Window	What to Look For
Bud break BBCH 07	Feb 15-Mar 15	Buds swelling and beginning to open; first green tissue visible
Leaf emergence BBCH 11	Mar 1-Apr 1	First leaves fully unfurled on new growth
Bloom start BBCH 61	Apr 1-Apr 30	First open flowers visible; flowers yellow
Bloom end / petal fall BBCH 69	Apr 15-May 15	Last petals falling; flower structures fading
Fruit/seed development BBCH 71	Jun 1-Aug 31	Fruit or seed structures forming; fruit color: red
Leaf drop BBCH 93	Oct 15-Nov 30	Leaves yellowing and dropping; no significant fall color display
Dormancy BBCH 97	Nov 15-Feb 28	Leafless; no active growth; dormant buds set

'Asplenifolia'

Common name: Asplenifolia Alder Buckthorn; Mature height: 10 ft

Hardy to USDA Zone 3

'Fine Line'

Common name: Fine Line Alder Buckthorn; Mature height: 5–7 ft

Hardy to USDA Zone 3