Family: Caprifoliaceae

There are around 150 species in this genus, the majority from Asia and North America. These shrubs or small trees originate from both temperate or subtropical regions and may be deciduous or evergreen. Mostly grown for their showy flowers, some are cultivated for out-standing autumn colour or brightly coloured berries, which often persist into autumn and winter. The evergreen species are often grown as hedging plants. Viburnums have simple, opposite leaves and mostly fragrant, dense, white flower heads. With some species, male and female plants are required for berry production, while others benefit from planting a second shrub to encourage cross-fertilization.

Species

V. x bodnantense, zone 7, is a decidu­ous shrub, to 3 m (110 ft) high. The oval, deep green leaves are paler on the undersides, colour­ing shades of orange, red and purple in autumn. The scented flowers are deep rose in bud, opening to pale pink from autumn to spring, and fading to white.

V. x burkwoodii (V. carlesii x V. utile), zone 5, is generally evergreen, to 2 m (6 ft), with an open habit. The clusters of flowers are pink in the bud in early spring, later open­ing to white.

V. x carlcephalum (V. carlesii x V. macrocephalum), zone 5, is an upright-growing, deciduous shrub, to 2.5 m (8 ft), which is very similar to V. carlesii. Large, rounded heads of fragrant, white flowers, tinged with red, appear in spring, and the leaves colour brilliantly in autumn.

V. carlesii, zone 5, native to Korea, is a densely foliaged, decidu­ous shrub, to 2 m (6 ft), with a spreading habit. The oval leaves are finely toothed at the mar-gins and the fragrant flowers are borne in dense clusters, opening in pale pink from mid to late spring, ageing to white. This species bears large clusters of red fruits, ripening to blueish black.

V. japonicum, zone 7, is a slow-growing ever-green, to 2 m (6 ft), with attractive, glossy, green, thick leaves and fragrant, white flowers, followed by red berries. This species is very similar to V. odoratissimum.

V. macrocephalum, Chinese snowball tree, zone 6, is a deciduous or evergreen shrub, growing to 3 m (10 ft), with dark green, leathery, oval leaves colouring red and yellow in autumn. In spring, the large, round, white flower heads, up to 15 cm (6 in) across, completely cover this shrub in a very showy display.

V. odoratissimum, sweet viburnum, zone 9, is an evergreen shrub or small tree, to 6 m (20 ft), suitable for warm to hot climates. Its thick, leathery, rounded leaves are glossy green and the small, white, tubular flowers, borne in dense clusters, are very fragrant. The red berries ripen to black.

V. opulus, common snowball or European guelder rose, zone 3, is a beautiful, deciduous shrub from Europe and North Africa grown for its flowers, autumn colour and clusters of translucent red berries, which persist after the leaves have fallen in autumn. The pure white, lacy flowers appear in clusters during spring, and its leaves resemble those of the maple. This species grows up to 4 m (13 ft) high.

V. plicatum forma tomentosum, zone 5, is a compact, rounded, deciduous shrub, grow­ing to 3 m (10 ft). Flat, rounded clusters of white flowers appear along the horizontal branches in late spring or summer and are followed by red berries. The leaves colour well in autumn.

V. plicatum 'Mariesii' flowers profusely, the branches displaying a tiered growth habit.

V. rhytidophyllum, zone 6, is a fast-growing evergreen, up to 3 m (10 ft) high, with long, dark green, deeply veined leaves, felted on the undersides. The large, flat clusters of creamy flowers appear at the branch ends in spring. These are followed by oval, red berries, matur­ing to black.

V. suspensum, zone 9, an ever-green to 2.5 m (8 ft), has oval, glossy, green leaves, paler beneath, and fragrant, creamy white to pink flowers, followed by red berries.

V. tinus, laurustinus, zone 7, is a densely foliaged, evergreen shrub, to 3 m (10 ft) high, although it may be taller. The oval, glossy, dark green leaves may develop reddish purple tones in cold weather. The pink buds in late winter open to white, and are followed by black berries. Native to the Mediterranean, this species is grown as a hedging or screening plant.

Cultivation

Viburnums may be grown in any reasonably rich, moist soil, but prefer a deep, well-drained, fertile loam, with plenty of water in summer. Grow them in sun or partial shade. For a more compact, dense bush, prune lightly after flowering. Propagate from seed sown in autumn, or from cuttings taken in summer. Viburnums may also be increased by layering or grafting.

Climate

There are species suited to various climatic zones. Most are very hardy.