Wild Things: Downy willow

A key component of one of the UK’s rarest habitats, downy willow is the subject of conservation efforts across much of its former range, writes Rich Rowe.

High among the crags grows a native willow tree that is in many ways symbolic of the health – or otherwise – of the high hills. Supremely adapted for life in extreme environments, downy willow (Salix lapponum) was once a dominant feature of a habitat known as montane (mountain) scrub – a type of low-growing subarctic woodland found in the transition zone between pine forests and the almost bare plateaux of the highest hills.

Subarctic scrub containing downy and other willow species is a rare habitat, now largely restricted to Scandinavia. Here in the UK, it is confined almost completely to the higher mountains of the Scottish Highlands where it persists in small, relic stands, although fragments also cling on in the Southern Uplands and parts of Cumbria (photo above shows spreading downy willow on crags near Helvellyn).

More shrub than tree – downy willow rarely grows above waist-height – this multi-branched species prefers moist, sheltered ground, usually with a northerly to easterly aspect. The bulk of those plants that still survive do so on precipitous ledges and gullies too steep to be accessed by deer and other browsing animals.

Being confined to unstable rock ledges and steep ground and with small and isolated reproducing populations, downy willows in the UK are quite literally teetering on the edge. But as a key component of landscape-scale native woodland restoration projects, work is being done by a variety of conservation organisations, including the John Muir Trust, to bring the species back from the edge in various locations.

In the Cairngorms, for example, partners from the Cairngorms Connect project have carried out a series of ‘Willow Walks’, taking thousands of downy willow saplings up and over the Cairngorm plateau for planting out in carefully planned locations away from grazing mouths.

This project to boost the existing downy willow population began several years ago when scientists first mapped every individual willow plant still present throughout the Cairngorms. During this research period, the Royal Botanic Garden Edinburgh found that the plants are still genetically diverse – a signal that they are remnants of a much larger historic population.

However, the belief is that any offspring of these remaining downy willows will likely lose genetic diversity, making them more fragile and less resilient to disease. One further challenge is that with each individual plant either male or female, even small groups of plants would be unable to reproduce if all are of the same sex.

To counter this, cuttings were taken from across the downy willow’s range and new, genetically diverse plants have been grown on in Trees for Life’s nursery at Dundreggan – with saplings then carried in adapted backpacks for planting around the Loch A’an basin on RSPB Scotland’s Abernethy reserve.

The hope is that this and many other similar projects will lead to the return of this lost habitat to many parts of upland Scotland, bringing valuable life and colour with it.

Further information

As part of the Thirlmere Resilience Partnership in Cumbria, the Trust has established an on-site tree nursery dedicated to propagating rare upland species from locally sourced seed. This includes the growing on of downy and tea-leaved willow, with planting out of saplings planned for this autumn within a dedicated montane scrub enclosure at Combe Crags. 

• This article first appeared in the Autumn / Winter 2025 edition of the John Muir Trust Members' Journal. If you would like to receive our Journal twice a year please consider joining the Trust as a Member.