Sarcococca (sweet box or Christmas box) is a genus of 11 species of flowering plants in the box family Buxaceae, native to eastern and southeast Asia and the Himalayas. They are slow-growing, monoecious, evergreen shrubs with leaves which are borne alternately. They are grown for their sweet honey scented flowers in winter. The fruit is a red or black drupe containing 1–3 seeds. They are tolerant of shade. The genus name Sarcococca comes from the Greek for ‘fleshy berry’, referring to the fruit.
Sarcococcas are not new to British gardens. The first to be introduced was S. hookeriana var. hookeriana, was discovered by Sir Joseph Dalton Hooker around 1825. It forms a compact suckering shrub up to 60cm tall, forming a neat clump of glossy, elliptic leaves, with small clusters of very fragrant creamy-white flowers with crimson anthers, followed by black berries. S. hookeriana var. digyna ‘Purple Stem’ AGM, has slender tapering shiny green leaves flushed bronze, and produces sweetly fragranced white flowers tinged bright pink at the base, which are borne on reddish stems. The flowers of these two small shrubs are a little pinker than the rest; the habit of S. digyna is more restrained than S. confusa and S. ruscifolia.
S. wallichii was discovered on the Singalila ridge near Darjeeling in 1821 by Nathaniel Wallich, described in 1916 by Otto Staph, but did not enter into British cultivation until 1994.
In 1980 Roy Lancaster collected and subsequently introduced S. ruscifolia v. chinensis from Yunnan in China. It has flowers all the way up the stem, followed by red berries. One form S. ruscifolia v. chinensis‘ Dragon Gate’ AGM was found growing at the entrance to the Dragon Gate temple, and is particularly good, flowering heavily and not getting too large at 1.5m.
S. confusa AGM has upright, green arching stems which grow from the ground to form a thick bush reaching a height of 2m. They have small, glossy dark green leaves. In late winter tiny but very fragrant flowers appear in the leaf axils. The flowers are followed by black berries that may persist the until the next flowering season. They prefer shade and do not require pruning.
S. humilis is the smallest species. It forms a compact bush and suckers freely, but this is easily controlled by pulling up the shoots. It grows to a height of 60 cm and a spread of 80 cm.
Sarcococca can tolerate pollution, can be grown in pots, and being evergreen create all year-round interest. They will survive dry shade, and they will grow in full sun provided the soil is moist; in drier conditions the leaves can turn yellow. They are very low maintenance, needing little to no regular pruning. If you need to prune out dead wood do it in mid to late spring.
The National Collection of Sarcococca is held by City of Sheffield Botanic Garden
Page image: Sarcococca hookeriana var. digyna (Image courtesy of HPS image library)