In my series on Britain’s native trees, I’m now picking my way through a very prickly carpet…
One of the most important trees in the Caledonian forest is also one of the most frequently overlooked: the juniper (Juniperus communis).
The juniper doesn’t really look like a tree at all, presumably because at some stage in its evolution it decided to take the path of least resistance and started hugging the ground in the face of relentless Atlantic gales. It is a ‘pioneer species’, preferring open spaces to germinate, and disliking shady conditions – and while this means that it gets a good dose of sunshine, it is also vulnerable to the worst extremes of weather.
Juniper is one of Britain’s three native conifers (Scots pine and yew are the others). It is thought to have spread here as the ice retreated around 12,000 years ago, seizing the opportunity of newly exposed earth and relying on its sharp needles for protection against grazing animals. As the woodlands grew up around it, the abundance of juniper may have taken a dip until Neolithic settlers started to make clearings in the forest, opening up new space for the cycle to begin again.
According to Trees for Life, common juniper has the widest distribution of any woody plant in the world, ranging right across the northern hemisphere from western Alaska to Japan. In Scotland it is found from the Borders right up to Orkney, but is most common in the Highlands. There are two sub-species: the prostrate form is ssp. nana, while ssp. communis makes a more upright, bush-like shape. On our own travels we have noticed it most frequently along the shores of Argyll but also in the Cairngorms, where it intermingles with the heather to produce a vivid carpet of pink and green. A plant of acid soils and peat, you might think – but strangely it also grows on the chalk downlands of England, including the Chilterns and Salisbury Plain.
“In Cairngorm, it occurs at the extreme treeline, extending into the heaths of the alpine zone up to an altitude of one thousand metres.”
‘The New Sylva’
A juniper bush can live for well over 100 years, and its cycle of reproduction is on a very long wavelength indeed. The plants are dioecious, meaning that they are either male or female; on the male plant, small yellow flowers release pollen into the wind, pollinating the pale green female cones which carry receptive droplets of fluid. It can take several years for these fertilised cones to darken into the familiar blue-grey berries with a dusky bloom and a deeply aromatic scent. These are eaten by birds – primarily migrant thrushes such as fieldfares and redwings – and once they have passed through their digestive system the seeds need to spend two cold winters in the ground before germination can take place.
Because of the dormancy period, it seems that the ebb and flow of juniper distribution is influenced to some extent by weather conditions or temperature, so that some years may spark a ‘flush’ of new seedlings; curiously, it has been observed at some sites that a generation of exclusively male or female plants may occur in a particular season. The juniper may have a hidden agenda, but as the cover dwindles and becomes split into increasingly distant groups, this phenomenon certainly isn’t helping its long-term prospects. Many bushes seem to be dying of old age without having reproduced in sufficient numbers to sustain the population.
A paper published by Plantlife in 2015 contained a wide-ranging report on juniper distribution in Scotland. Habitat loss and over-grazing are threatening its welfare, and the arrival of a disease called Phytophthora austrocedri, which infects the bush through its roots, is now causing major concern. There are new management programmes in place to protect the remaining populations, and meanwhile Trees for Life is continuing to plant juniper as one of the many native species included in its forest regeneration projects.
“Over 40 species of fungi plus a range of epiphytic lichens and bryophytes are known to be associated with the plant.”
Juniper has been called the ‘mountain yew’, and one source suggests that this may well be the origin of the Gaelic word ‘iubhair’, meaning ‘yew’, in some place names, rather than the yew tree itself. However, its leaves are nothing like those of the yew, which are quite soft and blunt-ended: juniper needles are like tiny daggers, guaranteed to give you a nasty shock in bare feet!
Red deer are not put off by the sharp needles, and will happily graze on the younger plants. On a smaller scale, its leaves provide sustenance for many moth caterpillars, among them the juniper carpet moth, the juniper pug and the chestnut-coloured carpet. Juniper bushes offer cover for nesting birds such as goldcrest, firecrest and black grouse, and the dense prickly mat helps to shelter seedlings of other trees.
Traditionally, juniper berries have been used for flavouring sauces, stews, and even cakes, and when mixed with wood shavings they give a wonderful aroma to smoked salmon. They are, however, best known for lending their distinctive fragrance to gin, whose name has a common origin with the word ‘juniper’. A couple of small distilleries are now producing gin flavoured with Scottish juniper berries, harvested in sustainable quantities. These include Crossbill Gin from Aviemore, which blends juniper berries and rosehips; and RockRose, made by Dunnet Bay Distillers from juniper berries in Caithness.
“The earliest recorded medicinal use of juniper berries occurs in an Egyptian papyrus dating back to 1500 BC, in a recipe to cure tapeworm infestations.”
Trees for Life
As a natural remedy, juniper berries are imbued with a wide range of properties, having been used to treat everything from rheumatism to typhoid. They have antiseptic qualities, and during the Spanish ‘flu epidemic of the early 1900s it was found that spraying a vapour made from juniper berries around hospital wards would limit the spread of infection.
In Scotland, Cornwall, and some parts of Central Europe there was once an age-old tradition of burning juniper wood at Beltane and on New Year’s morning, to rid houses and cattle of evil spirits. A juniper sprig was sometimes burnt next to the bed of a sick person, although in Iceland it was considered bad luck to bring both juniper and rowan into your house at the same time. The smoke of juniper was believed to aid clairvoyance.
“It was said that you would prosper if you dreamed of gathering juniper berries in winter, and the berries themselves signified honour or the birth of a boy.”
The Woodland Trust
- Forestry Commission
- ‘The State of Scotland’s Juniper in 2015‘ – Plantlife
- Trees for Life
- The Woodland Trust
- ‘The New Sylva‘ by Gabriel Hemery and Sarah Simblett
- White Dragon
- Dunnet Bay Distillers – Rock Rose Gin
- Crossbill Gin
Photos copyright © Jo & Colin Woolf