WARNING: LOCALLY INVASIVE SPECIES
Common Name: alder buckthorn
Type: Deciduous shrub
Zone: 3 to 7
Height: 12.00 to 15.00 feet
Spread: 3.00 to 4.00 feet
Bloom Time: May to June
Bloom Description: Whitish green
Sun: Full sun to part shade
Suggested Use: Naturalize
Easily grown in average, medium moisture, well-drained soils in full sun to part shade. Prefers consistent moisture. Adapts to a variety of soils. Species plants will self-seed, but new seedlings are not always true. Self-seeding can occur in optimum conditions. Best propagated from cuttings. Plant 24-30” apart for a hedge that may be pruned to desired height.
Rhamnus frangula is commonly called alder buckthorn because it is frequently seen in the wild growing in moist soils near alders (Alnus). It is also commonly called glossy buckthorn in reference to its glossy leaves. Glossy, oval to obovate, dark green leaves (to 3” long) retain green color well into fall, usually resulting in poor fall color. Insignificant whitish-green flowers appear in axillary clusters in May-June. Flowers are attractive to bees. Flowers are followed by inedible berries that ripen in July. Berries change from green to red to dark purple as they mature. Birds are attracted to the berries and help spread them over the landscape and into neighboring areas.
Genus name comes from the Greek name of various spiny shrubs.
‘Columnaris’, also known as tallhedge buckthorn, is a fastigiate, once patented cultivar that was originally grown by the patent holder from seed. It has been popular in commerce since the 1950s. It is a deciduous shrub that typically grows in a narrow fastigiate shape to 12-15’ tall but to only 4’ wide with its stems and branches erect, laterally compact, close together and sometimes twining. U.S. Plant Patent PP1,388 was issued April 26, 1955.
Japanese beetles, caterpillars and scale may appear. Nematodes can attack the roots. Watch for cankers, leaf spots and rust.
Hedge (may be pruned back every 1-2 years to maintain 3-4’ tall form). Also excellent privacy screen or narrow accent shrub. Foundations.