Let flowering shrubs brighten the winter garden. Their tiny flowers are tough, long lasting and crammed with an enticingly strong scent.

Take the small cream flowers of shrubby Lonicera fragrantissima. They suffuse the air with compelling fragrance. You know they’re frustratingly close but sometimes must act like a sniffer dog to track them down, hidden in a tangle of leaf-stripped twigs.

To enjoy a wonderful profusion of these flowers, you need to plant the shrub where it will enjoy sun and warmth in summer, so you shouldn’t plonk the shrub in a gloomy corner.

Hamamelis x intermedia, witch hazel, also rewards you when in a sunny place. The pale yellow flowers of ‘Pallida’ are probably the most fragrant witch hazel, especially when a touch of sun releases their best scent.

You’ll find orange and red Hamamelis cultivars are less strongly scented. And because they’re slow-growing, Hamamelis are understandably quite expensive. So check out their scent in the garden centre before lashing out for a plant.

One of the hardiest scented shrubs for Scotland is winter flowering Viburnum. I can’t see beyond Viburnum bodnantense ‘Dawn’. It’s always a joy to have a whiff every time I pass by on the way up to the duck run. A flush of little buds readily replaces any that have been blasted brown by frost and snow. Viburnum farreri and V. tinus also faithfully flower from November to February.

As ever, the low winter sun brings out Viburnum’s strongest scent, but even on a dull day you can inhale some of its spicy scent by getting up close and gently breathing on a flower cluster.

Although indispensable over the winter months, many of these shrubs disappoint for most of the year, so you wouldn’t want them to be too prominent. Equally, you do want to enjoy their show, so choose a place which you visit regularly, like near a shed or the log pile.

I’m thinking of shrubs like Mahonia japonica and M. x media. These evergreens do boast highly scented sprays of the tiniest yellow buttons, so don’t banish them to the gloomiest corner just because they’re tough woodland edge plants. Why not plant them where you’ll actually see them?

We all know that like taste, we simply don’t have the vocabulary to describe scent. We know what we mean but can rarely share it. This is why I was attracted to Isabel Bannerman’s sumptuous book, “Scent Magic” [Pimpernel Press 2019].

I do find some of Bannerman’s passages a wee bit flowery, but she does have an evocative style. She has a much wider choice of plants in Cornwall than we could ever grow in this country, but we can “enjoy the great hug of warmth, a buttery, spicy smell” produced by the small, white flowers of Sarcococca, ‘Christmas box’.

All these scented flowers play an important part in the garden. Those that aren’t wind-pollinated need small flies, moths and, at the end of winter, emerging bumblebees, for pollination, just as these creatures need rich nectar.

So I’m horrified to think that air pollution can weaken this scent so that needy insects can’t easily sniff out the flowers, which in turn aren’t pollinated.

Studies at the University of Virginia and at Penn State have shown that the scent molecules emitted by plants bind with atmospheric pollutants and are thus chemically altered so the scent of the flower is damaged.

"We found that when we confused the bees' environment by modifying the gases present in the atmosphere, they spent more time foraging and would bring back less food, which would affect their colonies," said Prof. J.J.Fuentes, Penn State University.

Plant of the week

The Grand Fir, Abies grandis, makes the most fragrant Christmas tree, smelling resiny, fresh and slightly of celery. Flat, dense needles and good blue/green colour.