Christmas box is so-called because, in most years, it begins to flower in late December. The first indication that it is in flower comes on a mild winter day, when its sweet fragrance is detected.

For anybody who knows the plant, they will instantly know the source and approach it for a better sniff, or, if it cannot be seen, will look around to find it.

Even though its scent is sweet and so often a lovely surprise, this is not a well-known shrub, despite its attractive common names, both of which happen to be accurate.

The reason it is not well-known would seem to be that its flowers, though scented, are very inconspicuous. They have no petals, and the remaining fertile parts of the flowers are small and tucked away under the leafy branches for protection from wind and rain.

This shrub has come to rely entirely on its generous production of sweet scent to attract pollinating insects, which are not much seen in cold, wintry weather. So there is not much value for a plant in producing colourful petals that wind, rain and frost, would destroy.

Instead this plant has evolved an interesting strategy. On mild days, when temperature levels rise to over the critical 10°C, bees do a little foraging, and the plant releases its perfume in good timing.

The pollen-carrying stamens are short and white or greenish white, hardly visible, but the bees have no trouble finding them because the scent easily carries on the breeze.

Though relatively unknown, Christmas box is available in many garden centres in one or other of its several species and forms. Its botanical name is Sarcococca hookeriana, native to China and hardy in gardens.

This species forms a dense bush to about 1.5m high and the same across. It tends to sucker outwards to make a rounded shape, but it is not a nuisance suckering plant.

It has white flowers followed by shiny black berries, which often persist right through flowering the following winter and spring.

There is a smaller species, Sarcococca humilis, which reaches only 70cm or so, with dark green leaves and pinkish flowers.

This short form is often considered to be just a botanical version of the first species, as it the variety digyna, which has more attractive narrow leaves, and a purple-bark version called ‘Purple Stem’ is pretty with pink flowers.

Another species, Sarcococca confusa, is similar, not tall, with tapering dark-green shiny leaves. Though less often seen than the others, Sarcococca ruscifolia, has dark green leaves and red berries.

Sweet box is part of the box family, buxus, the plant that is used for box hedging, but, though sometimes mentioned as a sweetly scented alternative, now that box blight has threatened box hedging, sarcococca is not suitable for hedging because it spreads slowly by suckering and the hedge would simply creep outwards into the beds its encloses.

It is a perfect plant for a rural garden, where there is space for it to make a good-sized bush. A place can be found for it in an out of the way corner, as it does not need to be in a position of prominence.

It is tolerant of shade and thrives with little direct sunlight. In fact, it tends to burn out in the sunshine. It grows in any soil that is not wet and it loves lots of leaf mould in the soil.

It has a habit of producing its first few flowers low down on the bush, and a few of these stems can be snipped off and taken indoors in water for their sweet scent.

Christmas plants

Plants, such as poinsettia, cyclamen, potmums and azalea, are popular in the festive season for gifts, and to decorate the home. While these are robust plants, they are challenged by the conditions indoors at this time of year. Houses tend to be heated more than usual, the air is dry, and it is all too easy to forget to water them.

New plants should be given a relatively cool room, though still heated, for a few days to settle down from their journey. Give them enough water to dampen, but not wet, the compost and they should not be left standing in a saucer of water. Then, they can be placed in a warmer room, in good light, though not near a source of heat and not behind the curtains, unless the window is double-glazed.

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Trees, shrubs and roses

Although there may not be a great urge to work in the garden now, some small things can be done with trees and shrubs. New ones can be planted and those planted in the wrong place can be lifted and moved, if not too big. Check young trees are properly staked going in to winter gales.

Flowers

Bedding plants for spring colour should have been planted by now, but wallflowers, pansies and bachelors buttons can be planted, especially as they are available in pots. Lift cannas, dahlias and begonias in inland areas, or cover with soil to keep frost off. Any spring bulbs should be planted.

Lawn

Lawn mosskiller, such as sulphate of iron can still be applied. Moss will grow vigorously in the coming damp months. An occasional mowing during winter is a good idea if the soil is not squelching wet. If there is drainage under the lawn, check it is working with a flow of water at the outlet.

Fruit, vegetables and herbs

Tree, bush and cane fruits can be pruned now, if this has not been done already, but not plums or cherries, which are pruned in summer. Dig over vegetable ground in dry weather. Plant new fruit trees and bushes. Control grass and weeds near fruit trees and bushes, unless mature.

Greenhouse and house plants

Give very little water to reduce the risk of grey mould disease. A small electric frost protection heater will save tender plants, such as geraniums or fuchsias, in a greenhouse or unheated conservatory. If you have time, wash down the greenhouse walls to reduce algae and improve light.