In this article I am going to write about the Rowan tree, better known to horticulturalists as Sorbus. It is one of Scotland’s most famous trees, sung about by countless generations of Scots both at home and overseas and regarded by many as a talisman to ward off evil spirits.
The genus contains over 100 different species of deciduous trees and shrubs which are widely distributed, mostly in Northern temperate regions. As well as being common in the Lothians, they are found on hills and mountains, often growing on scree.
Most varieties are quite attractive when flowering (mainly white) and many types have quite striking Autumn foliage, with colours ranging from fiery reds, oranges, golden yellow, through to bronze and purple shades. The forms with white and yellow berries hold their Autumn colours longer than those with red and orange fruits. In most years, the white flowers appear from May through to June, with the berries colouring up very quickly at the onset of Autumn and hanging in great clusters as winter feeding for the birds.
They are easily grown in any fertile, well drained soil and will also survive in clay conditions and damp sites. Local authorities use them often in industrial areas where they are very tolerant of atmospheric pollution. The whitebeam section (aria types) are used to great effect in very exposed, windy sites where the bright, silvery undersides of their leaves are best shown off.
Many of the varieties lend themselves well to small, suburban gardens, while others are better suited to wild or woodland gardens. A few varieties are dwarf trees, some are shrubs and others develop into really large specimens.
It is not advisable to eat the raw fruits as they can cause stomach upset, although, during the First World War, many people collected them and made rowan jelly which can still be made today (ask your granny!)
Sorbus aria Lutescens, illustrated above, is ideal for an exposed site, having large leaves with silvery undersides.
Sorbus Aucuparia is the native rowan, with masses of red berries and various shades of bronze and red in autumn.
Sorbus Cashmeriana is a beautiful small tree, with pink flowers and large, white berries.
Sorbus Hupensis is a strong growing but small tree with distinctive bluish-green leaves, turning to fiery red in autumn, along with pink tinged berries.
Sorbus Joseph Rock is a small tree with an erect, compact head and amber yellow berries.
Sorbus Reducta is a native of China. It is ideal for the rock garden as it forms a low thicket of upright branches and is just 300mm tall. It has small, grey-green leaves which turn bronze red in autumn. In early summer, it has loose clusters of flat, white flowers, followed by pink berries.