Sarcococca confusa Seeds | Sweet Box
LATIN NAME: Sarcococca confusa
COMMON NAME: Sweet Box
Plant Profile
The plant is a dense, rounded evergreen that usually stays under two metres and spreads wider than it stands. It was named by the botanist Sealy, who recognised that the cultivated material matched none of the described Chinese species, and its probable parentage lies between the Himalayan and Chinese members of the genus.
The flowers are small, greenish-white and clustered in the leaf axils along the previous season’s wood, and each is little more than a ring of sepals around a central column of stamens. There are no petals. The scent is produced by the sepals. Winter-active flies and the first bees of the year work the flowers for nectar.
Sweet box is one of the most shade-tolerant evergreen shrubs in general cultivation, and it will grow and flower in the dry shadow beneath mature trees where most plants fail. It manages there because its leathery leaves are long-lived and efficient at low light, and because it keeps those leaves through winter, when the canopy above it is bare and light reaches the ground.
Science & Biotechnology
The box family is chemically distinctive, and Sarcococca shares the steroidal alkaloid chemistry that makes the family interesting to chemists. The compounds recorded from the genus are pregnane-type steroidal alkaloids, among them epipachysamine and the sarcorucinine group, built on a steroid skeleton rather than the simpler nitrogen ring systems of many plant poisons.
The fruit is a fleshy black berry, glossy and about the size of a small pea, ripening in the second half of the year and hanging under the leaves where it is easy to miss. Each berry contains a few hard seeds. They are not food, and the alkaloids are present in them.
Uses & Benefits
Sweet box is almost always sold as a clone. Semi-ripe cuttings taken in late summer with a heel of older wood root readily in a closed frame, and the trade also uses micropropagation, in which shoot tips are established on a low-cytokinin medium, multiplied as axillary shoots and rooted in vitro before hardening off. Clonal propagation holds the heavy flowering and the particular scent of a chosen plant.
As a hedging plant, sweet box is used at low height, roughly half a metre to a metre, and it takes clipping in early spring after flowering. Plant about forty centimetres apart for a dense line, or wider if you will wait an extra season for it to close. Rows along a north-facing wall or under deciduous trees are the classic positions, and it will also grow in a large container in shade.
Cut a few stems with the flowers just open and stand them in water in a cool room; the scent will carry across a whole hallway. The same stems, brought indoors, are a good way to find out whether the fragrance of your particular plant is the one you want before you propagate from it.
Growing from Seed
Seed is set freely and can be collected from the black berries when they soften. Clean the flesh off, sow in a pan of leaf-mould-rich compost, and leave the pan outside in a shaded frame through the winter, because the seed wants cold and damp before it will sprout. Keep the medium moist but never wet, and do not let the pan dry out in a mild spell, which is when most sowings of this genus fail.
Sweet box is slow, and a new hedge looks thin for two seasons. Plant small plants rather than large ones, keep them watered through their first summer, and mulch with leaf mould each autumn. Once established, a light trim in spring and an occasional handful of compost is all the attention the plant wants.
Our Take
Plant sweet box where you walk past it in winter, because the whole point of it is the scent, and put it in the shade that defeats everything else. A near relative, Sarcococca hookeriana, is a little taller and suckers into a thicket, which is useful on a difficult bank. If you are building a low evergreen framework for a shaded garden, Buxus sinica gives the same fine texture without the perfume, and the smaller-leaved Chinese boxwood will clip into a tighter line still.
Related Reading
More species in the same orbit as Sweet Box: