In the subdued winter garden, an intoxicating scent is a joy
At this time of the year, when all is fairly muted outdoors, there's nothing better than walking into a garden and being clobbered over the head by an unexpected scent. One of the most powerful emitters of winter fragrance is Daphne bholua 'Jacqueline Postill', an evergreen shrub with clusters of dainty shell-pink flowers. It was named after the wife of Alan Postill, the propagator who raised it at Hillier's nursery in 1982 (it was a seedling of the equally-perfumed, but deciduous 'Gurkha'). Mrs Postill must have been tickled pink to be synonymous with one of the most gorgeously-scented plants in the world. Yet her namesake's odour, so intoxicating to humans, is not aimed at our species at all - but at various individuals in the insect fraternity.
Flower scent is one of a plant's many tricks to attract pollinators. Unlike animals, members of the floral kingdom can't go walkabout (or flyabout, or swimabout) looking for a mate, so they have to employ wiles to get a creature to ferry their pollen - which contains the male gametes - for them. Some flowers mimic the smell of the female pheromones of specific insects, and when hopeful suitors come flying in they are dusted with pollen as they search for a consort, or while they attempt to mate with the flower. Other blooms simply smell like food, and may offer the foraging creature rewards of nectar, wax or pollen in return for hauling a bit of pollen to another flower.
Winter-flowering plants are often highly scented because they have to shout loudly, as it were, in the hope that the few pollinators that are about in the cold weather will notice them.
There are other early-blooming daphnes beside D. bholua that kick off a powerful perfume. D. odora is evergreen and bears pink-edged white blossom, while for those who are fans of variegated foliage, the cultivar 'Aureomarginata' has gold-edged leaves; D. laureoloa, the spurge laurel, is also evergreen and has almost invisible yellow flowers that are spasmodically fragrant; D. mezereon has whitish or purple flowers (depending on the cultivar) on bare stems; and the low-growing evergreen D. blagayana bears cream flowers, and is much favoured by alpine gardeners.
Daphnes have a reputation for being fussy, and for upping and dying for no good reason. Most like a fertile soil with plenty of humus, and they usually flower better when in a sunny position. But don't let their roots bake, or don't let them get waterlogged. And for heaven's sake don't dream of moving them once they have been planted, as they "resent disturbance", as the books say. Many get so resentful they expire from the emotion. If yours should pass away, however, be consoled that if it is Himalayan species, a very fine paper, known as "lokta" can be made from the inner bark.
Some of the viburnums also bloom odoriferously in winter. Perhaps the best known is the deciduous V x bodnantense 'Dawn'. It flowers for months on end, starting in autumn while it is still wearing its leaves. But, it is most beautiful on a clear day in midwinter when the stems are naked, and the pink tubular flowers can be seen against the backdrop of a blue sky. It has an upright habit, sending shoots up from the base of the plant. This tall vase shape should be preserved, so don't be tempted to prune it anywhere other than near the base, and even then, don't do more than remove weak, damaged, or ungainly stems. V farreri, one of the progenitors of the above plant, has pink-tinged white flowers, and as it gets older, a more spreading habit than its offspring. Neither of these viburnums is terribly exciting when not in flower, but they make handy climbing frames in summer for scrambling plants such as clematis.
Sarcococca confusa and S. hookeriana, also known as Christmas box, are dwarf evergreen shrubs with small and glossy leaves. They bear small, tufty flowers of white and pinkish-white respectively, which are sweetly scented. They are happy in shade, as long as it is not too dry, so they are handy little plants to stick in awkward spaces.
Yellow flowers are especially cheering at this time of the year, as they catch the sun and bounce its brightness about the garden. The mahonias, of which there are plenty, produce racemes of fragrant, canary-coloured blossom, carried above their prehistoric-looking, evergreen spiny foliage. The Chinese species, M. japonica (which is Chinese, despite the name meaning "of Japan") and M. lomariifolia and the many cultivars that have arisen from their cross, M. x media, have a more striking and upright shape than the American Oregon grape, M. aquifolium.
The witch hazels (Hamamelis) are another genus that occurs in both Asia and north America. The yellow-flowered Hamamelis x intermedia 'Pallida', discovered 50 years ago at RHS Wisley Garden in Surrey, is reputed to be the most perfumed. The yellow witch hazels are more scented than the other colours. The popular, Tequila-sunrise-coloured 'Jelena' is nearly odourless, while the deep red 'Diane' has barely a whiff. Garden writer, Stephen Lacey, claims that the reds and oranges have a musty, "fruit spice scent that is exactly the smell of parrots" (which makes me want to find a parrot to sniff). Witch hazels prefer a moist acid soil, and need sun to flower properly. Their raggedy, tassels of blossom look just like shredded crêpe paper, and beg to be examined closely.
A final producer of heroic quantities of scent at this time of the year is the evergreen tree Azara microphylla from Chile. A variety with cream-edged leaves, 'Variegata' originated sometime before 1910 at Belgrove House in Cobh, the home of William Edward Gumbleton. The masses of tiny flowers are almost hidden under the leaves, so you hardly see them, but their strong vanilla fragrance gives the cold winter nose several thousand reasons to be cheerful.