A splash of colour in the monochrome months

Dr Trevor Dines is a botanical specialist at Plantlife. Here he explores the colours of flowers during the winter months. 

For many lovers of wildflowers, winter is the quiet time, the down time, the lull in the botanical calendar. Gone are the spring woodlands awash with pools of blue and white, the bright days of June with meadows in full throttle, and of August barley fields blazing red under a hot sun. It’s time to put away the hand-lens and the identification books, for the long monochrome months are here.

And yet, of course, that’s just not true. If you’re prepared to brave the elements there’s plenty to see in winter, and finding a bit of unexpected colour is always especially rewarding. This year is particularly fun, as the record-breaking mild temperatures mean the countryside is still specked with flowers.

Some plants are actually programmed to flower at this time of year. Gorse is king of the season, and if it’s in flower now it’s likely to be common gorse (Ulex europaeus) – both western gorse (Ulex gallii) and dwarf gorse (Ulex minor) flower in summer and autumn. Common gorse begins its display in late autumn and finishes with a triumphant flourish of flowers in spring. This seemingly continuous display, though, actually comes from two different forms of common gorse that grow side-by-side: some bushes flower with small number of blooms over a long period in winter, while others flower abundantly for a shorter period in the spring. This strategy has been adopted to help overcome predation by a small weevil. Exapion weevils emerge in spring and can attack up to 95% of seed pods. Bushes that flower and produce their seed pods in winter therefore escape this predation, while those that bloom in spring flower so abundantly that a greater number of the pods survive. Surprisingly, the level of pollination in winter and spring is similar; mild winter days will see pollinators emerge and, with very little else in flower, they’ll flock to the only restaurant in town that’s open.

While we’re on the subject of gorse, it always amuses me when people say the scent of their flowers reminds them of coconut. Coconuts only received widespread popularity in Britain in the 1830s, so presumably, for some time, people would remark that the scent of this new novelty reminded them of gorse. In an attempt to keep connected to our own native flora, I like to maintain the comparison and whenever I smell a coconut I try to think, “oh yes, that reminds me of gorse”.

Another winter-flowering plant is hazel (Corylus avellana). To be more accurate, hazel produces its catkins during the winter, but these usually remain tightly closed, like little versions of those Liquorice Torpedo sweets, only not quite so brightly coloured. Typically, these catkins elongate and open with the warmth of spring from mid-February onwards, taking on the appearance of lambs-tail’s hanging from the branches. But it’s been so mild this year that open hazel catkins have already been reported across much of Britain. If you spot them in woods and hedgerows near you, remember that these are the male flowers, the structures designed to shed their pollen into the wind. The tiny female flowers are much less conspicuous but are well worth seeking out as they’re beautiful. Have a look on twigs around the open catkins and you should find what look like fat little flask-shaped buds with a tuft of bright red or pinkish-red hairs. These are the female flowers with stigmas sticking out to catch the passing pollen. They always remind me of tiny red fireworks exploding on the branches.

It’s not just flowers that can be seen now. One of my favourite ferns - the Polypody (Polypodium vulgare) – is worth seeking out at this time of year too for its incredible spores. Unlike most of our ferns, which die down in winter and produce a flush of new fronds each spring, polypody produces its new fronds in late summer. The slightly leathery leaves are deeply cut into a herringbone pattern and stay fresh and green all winter. Look for them on laneside banks, walls, tree trunks and in rocky woodland and if you find a clump, turn a frond over. You should see a wonderful pattern of bright yellow or brownish dots. These are sori – clusters of structures containing ripe spores (the fern’s equivalent of seeds) - and these spores are ready for dispersal through autumn and winter. But the polypody doesn’t leave dispersal entirely to the wind. The spores are held in odd little structures called sporangia. Imagine a baseball player’s glove tightly closed around a handful of marbles and you’ll get the idea. On dry days, a line of cells around the sporangium dries out and causes the structure to split and curl backwards – our metaphoric baseball player curls his wrist back and bends his forearm backwards. Suddenly, the cells rupture, spring back to their original position and the spores are catapulted from the sporangium - the baseball player flicks his forearm and wrist and sends the marbles flying. Incredibly, the spores can reach a speed of 10 metres a second and can be flung a considerable distance from the parent plant. You might want to step back a little!

Of course, it’s the flowers that really catch our eye at this time of year, rather than flying spores. This year has been exceptionally mild, although I’m always mindful of a paper on the subject written nearly 150 years ago lamenting the annual lists of flowers that are published in newspapers every December and January “...as evidence of the extraordinary mildness of the season”. But a record-breaking average UK December temperature of 8oC is unusual, and a huge range of plants are either continuing to flower or are flowering early. In the New Year Plant Hunt, a survey of what’s in flower at the start of the year arranged by the Botanical Society of the British Isles, an astonishing 612 species of plants were recorded in flower. Social media was full of the flowers found, including very out-of-season plants like ivy broomrape, hawthorn and milkwort. Many people were recording 10-20 species in flower, some got up to the 40s and one even reported 77 different plants in bloom.

But this shouldn’t really come as a surprise. We must remember that plants are adaptable and opportunistic; if there's a chance to set some seed they'll take it. Species adopt several different strategies to flower during the winter months; there are summer-repeaters (summer flowering plants like oxeye daisy that can have another go in winter), continual bloomers (things such as white deadnettle that just seem to keep going all year-round), cornfield opportunists (annuals like field pansy that can germinate in late summer and flower in winter if it’s mild) and, of course, those precocious spring flowers, usually woodland plants such as violets and dog’s-mercury, that just get away early if it’s very mild. For more on these and other strategies that winter flowering plants adopt, visit the Plantlife website. 

So enjoy the winter! These might be the monochrome months, but they’re not without colour if you’re prepared to look.