The Coastal Cliffs - Shetland's Hanging Gardens
Da Banks, or sea cliffs, have some of the lushest vegetation in the islands. Along the closely-grazed turf of the clifftops, Sea Pink and the tiny blue flowers of Spring Squill are prominent from late May through to early July. On ungrazed sections they're joined by Sea Plantain, Buck's-Horn Plantain and, on the more sheltered cliffs, by Roseroot, Sea Campion, Red Campion, Scurvy Grass, Bird's-Foot Trefoil, Sheep's-Bit and Thyme. These species all flourish despite the poor soils, rapid drainage and exposure to violent winter winds and salt spray.
Roseroot copes by having very succulent leaves which allow it to conserve fresh water, in the same way as cacti plant. Spring Squill, Sea Pink and Sea Plantain do the same, while Scots Lovage, another plant frequent on inaccessible cliffs, adapts to the short growing season in Shetland by maximising growth early in the year.
How Green Were Our Valleys...?
The profusion of plant life on the cliffs – in what amounts, at least in winter, to a frigid, salt-lashed desert – leads one to wonder just how green the hills and valleys of Shetland must have been before humans imported sheep and fire, some 7,000 years ago.
In just a few places some stunted native trees have survived, such as the single Hazel at Catfirth in Nesting, the Rowans on loch islands in Northmavine and Shetland's last wild Crab-apples on a cliff face at Fora Ness in Delting. In recent years the Shetland Amenity Trust has sponsored schemes to restore at least some of Shetland's native trees and shrubs, helped by many enthusiastic local gardeners.
The Arctic Alpines
On Shetland's highest summit, Ronas Hill (1,475' / 450m) conditions can be as extreme as at the top of Cairngorm. Vegetation is sparse and plants have adapted by growing low, creeping or forming hummocks on bare, exposed granite debris. About 15 Arctic-Alpine species grow on the hill, including Alpine Lady's Mantle and Moss Campion.
The eastern hills of Unst are not as high but, because of the peculiar geochemistry of the rocks on the Keen of Hamar National Nature Reserve, a similar tundra-like habitat of stony soils has developed. Here grow the only examples in the world of Edmondston's (Shetland) Mouse-ear, a beautiful little chickweed named after Unst's famous 19th century teenage botanist, Thomas Edmondston, killed accidentally in Peru while on an expedition in the steps of Charles Darwin.