Description
Rhamnus – Frangula – Buckthorn –
There are about 125 species of prickly, deciduous or evergreen shrubs or small tress, in the Buckthorn family, in this genus. They are widely distributed in Northern temperate regions, with a few in the Southern Hemisphere. They occur in woodland, heath land, scrub, bogs, or rocky places, often on alkaline soils. They are grown primarily for their leaves, which has good autumn color in some of the deciduous species, and their decorative fruits. The leaves are simple often with serrated edges and are held opposite or alternate. Tiny hermaphrodite or unisexual, cup shaped flowers, up to 1/8″ across, with 4 or 5 petals, are borne in axillary racemes or umbel like clusters, they are often fragrant and usually yellowish white, greenish white, or white. Some flowers, particularly those of R. frangula, are very attractive to bees. The fruits are fleshy, pea sized berries popular with birds. Grow in a shrub border, R. cathartica and R. frangula may be used as hedging. All parts may cause severe discomfort if ingested.
Grow in moderately fertile soil in full sun or partial shade. R. cathartica, R. frangula, and R. imeretina prefer moist soils. R. alaternus needs well drained soil in full sun. They tolerate salt laden air and alkaline soil.
Prone to scale insects, caterpillars, rust, Cercospora leaf spots, and Septoria leaf spots.
R. frangula ‘Columnaris’ – Tallhedge Buckthorn – Alder Buckthorn – This bushy, narrow, upright deciduous shrub, grows 10-15′ feet tall and just 3” feet wide. It produces oval, glossy, dark green leaves, to 3″ long, with light green underside and can be hairy, which turn red in autumn. In late spring and early summer, it bears insignificant axillary clusters of hermaphrodite green flowers, that attract bees. In autumn it bears fleshy, spherical red fruit, to ½” diameter, ripening to black in autumn. Used as hedging a plant
Zones 3-8
