Visit the Outer Hebrides for the white rose and an insect idyll

The Outer Hebrides are a remote and outstandingly beautiful and diverse chain of islands off the northwest of Scotland. Scientists describe their sustainably managed, species-rich dune grasslands as one of the rarest habitats in Europe and they have been awarded Site of Special Scientific Interest status. For much of the year this land provides sparse grazing for the crofters’ livestock, but in summer the machair – the Gaelic name for a fertile, low-lying grassy plain – is a luxurious and abundant carpet of bright wildflowers buzzing with insect life and the air is full
of threatened birds, such as corncrakes.

The islands’ sand dunes are stabilised by banks of marram grass. They protect the flat, fragile thin-soiled land behind them, but during the thousands of years since the last ice age, powerful Atlantic gales have blown ashore fine fragments of crushed calcareous seashell mixed with sand. Falling beyond the dunes this has enriched the soils, and the land has long been farmed using the traditional non-intensive method of crofting (where pesticides and chemical fertilisers are not used). The ground is worked in rotation, providing regular opportunities for annual plants to seed and establish. Washed-up seaweed is used as fertiliser and soil improver, and carefully ploughed into cultivated areas.

Inspiration for the trip

As an undergraduate in Aberdeen, I fell for Scotland and discovered the Aberdonian horticulturist and botanical artist Mary McMurtrie. She wrote her first book – the inspiring Wild Flowers of Scotland – in 1982, aged 80, and became recognised as the oldest working artist in Britain. Her Scots Roses of Hedgerows and Wild Gardens is the best source of illustrations for Scots roses.

When to go

The prolific populations of primrose, marsh marigold and flag iris bloom in May. The machair grassland flowers from June to early September. It is best to plan well ahead as transport and accommodation are limited and fill up quickly.

Where to go

A walk of just a few miles in South Uist will allow you to explore the coastal machair, pass through the transitional croft-line (where the croft cottages are) and on to the moors of Loch Druidibeg, home to nesting wading birds and golden eagles. Here tough plants have colonised the peat bog, adapting to the low-nutrient content of damp, acidic soil. Look closely and the sombre expanses yield plenty of colour; violet-flowered butterworts (Pinguicula vulgaris), the golden blooms of tormentil (Potentilla erecta) and bog aspodel (Narthecium ossifragum), a distant relative to both irises and lilies. The pink lousewort (Pedicularis sylvatica) and heath spotted orchid (Dactylorhiza maculata) also grow here.

Tiny flashes of blue are the common and heath milkworts (Polygala serpyllifolia). Cotton grass (Eriophorum angustifolium) is perhaps the most chameleon of all, with silky and lustrous tassels of antique white in the sun, or grubby forlorn mop heads in the rain. Heath and heathers dominate but among them are low clusters of woody bog myrtle (Myrica gale) exuding a sweet, resinous smell that is good for keeping midges away.

Both fallow and crop areas of machair can be species rich, a riot of corn marigold (Glebionis segetum), buttercups, useful red clover (Trifolium pratense) that enriches the grassland by trapping atmospheric nitrogen in its roots to form nitrate in the soil, glowing kidney vetch, harebells (Campanula rotundifolia) and knapweed, which is a favourite of bees.

The coastal hamlet of Northton on Harris has an exhilarating hike that winds through acres of machair and on up to the peak of Ceapabhal (368m).

The views of the vast azure expanse of Luskentyre Bay below and the bright tangle of flowering machair are unforgettable. Iris and marsh marigold colonise damp pockets alongside the less familiar bogbean (Menyanthes trifoliata), a robust and medicinally useful plant of fresh water, its stiff, leathery foliage an odd contrast to prettily fringed, arresting flowerheads.

Plant to grow at home

It is best to appreciate the machair flora as a habitat, and not select one species to try at home. However, a pretty little rose caught my eye while I was on Harris, and November is the bare root rose planting season. Rosa spinosissima is the traditional white rose of Scotland, eulogised in song and poetry and second only to the Scottish thistle in emblematic renown. It came into cultivation at the very end of the 18th century and by 1820 hundreds of double forms had been selected. Gertrude Jekyll was fond of Scots roses, frequently using them in her gardens.

The most northerly of any wild rose, Rosa spinosissima is a hardy, prickly stemmed, deciduous shrub teeming with small, creamy white, fragrant flowers. Its common name, burnet rose, comes from the close resemblance of its compound foliage to the herb burnet (Sanguisorba minor), this forms a lovely fresh foil for the deep-purple-black globular hips that follow. These were traditionally used in the dying of local cloth. A plant of poor land, in the wild it forms dense patches on sand dunes and sandy heaths, venturing further inland on limestone soils. In the garden select a location exposed to full sun, it is unfussy about soil, is wind tolerant and drought resistant once established. This is a lovely rose for wilder areas of the garden, its low growing habit making it ideal groundcover.