2011 is shaping up to be a bumper year for fruit and berries. All of the hot sun and near-drought conditions of Spring allowed the mass-pollination of flowers by feeding insects – unhindered, this year, by rain or heavy cloud – whilst the recent summer rains have promoted the swelling of the subsequent fruit to terrific proportions. Our hedgerows are filled with the glowing gold and scarlet of Viburnum berries along with the over-sized, ebony-black hips of wild roses, and will soon be heavily laden with what looks to be a bumper crop of blackberries too. Elsewhere Malus (Apples and Crab-Apples) are all developing nicely, but they have been well and truly eclipsed by their close relatives the Sorbus, or Rowans, whose giant clusters of bright orange-red fruit seem to be festooning their owners branches with unusual abundance this year.
Our native species of Rowan, also known as the Mountain Ash, is Sorbus aucuparia. This is one of nearly 100 species of Rowan within the Sorbus genus, Sorbus being an unusual genus in that it is sub-divided into two very distinct sections: the Rowans (Aucuparia section) and the Whitebeams (Aria section). As the common name “Moutain Ash” implies, the species is a specialist of uplands, and very often forms the final tree line at higher elevations, with twisted, wind-blasted specimens often found clinging on in the most improbable and inhospitable sites. Although entirely unrelated to the Ash (Fraxinus species) Rowans do share the pinnate arrangement of their foliage with that genus, and all Rowan species have leaves that are divided into feather-like or fern-like fingers – the pinnae.

A single Rowan leaf, divided into feather-like pinnae or leaflets, which are themselves toothed at the margins.
Rowans have adapted not just to exposure and high elevation, but also to extremely acid soil conditions, where few other woody plants would survive. Such conditions are typical of our moorlands, of course, but, aside from out-and-out alkaline chalk-lands, Rowans are perfectly adaptable and thrive in virtually all soils. This adaptability, along with their general toughness and lack of major pests and diseases has seen Rowans widely used as street trees and in parkland plantings, but in many ways they are also amongst the very finest possible trees for planting in gardens. In common with most Rowans, Sorbus aucuparia is a small tree, with a delicate airy habit. That divided foliage ensures that no Rowan casts heavy shade, which in turn makes them ideal for under-planting with smaller shrubs and herbaceous plants. The leaves of the Rowan are also inherently attractive throughout the growing season, but take on a particular appeal in autumn when they start to tint to shades of red-purple and bronze.
Back in Springtime the trees produce large, and very densely packed corymbs of tiny, cream-coloured flowers. The flowering display is not generally considered of great ornamental interest, although I think they do have a bumptious, fluffy appeal, but, in common with many other creamy spring flowers, they are hugely attractive to bees, hoverflies and other pollen and nectar feeding insects. Finally, then, the result of all that feverish insect attention are the magnificent berries, produced well in advance of many other trees and in full scarlet effect by August.
Rowans would be well-loved and widely planted solely for the ornamental effects of those berries alone, notwithstanding all the many other attributes that the trees have to offer, but the fruits are equally esteemed by many species of birds who often flock to the trees throughout autumn. Thrushes, Redwings are Waxwings are all devotees, and many other species will also make a detour to a garden bearing a fruiting Rowan tree. We humans too have long harvested the fruit to produce Rowan jelly – a marvellous preserve with a sharp, marmalade-like flavour.
As already mentioned, our native Sorbus aucuparia is just one of a large number of species of Rowan, and many new species have recently been discovered, named and introduced into cultivation following recent plant-hunting expeditions to the mountainous regions of South-Western China. Our native tree is well up there amongst the best of the genus, ornamentally speaking, but almost all of the species and their ever-expanding collection of hybrids are highly attractive, incredibly easy to accommodate and exceedingly well-worth seeking out and growing.

In a good season some Sorbus can produce jaw-dropping leaf colour - this is Sorbus sargentiana in full autumn finery.
There are a few much larger growing species, most notably the magnificent Chinese Sorbus sargentiana, with it’s huge sticky over-wintering leaf-buds, and 30cm long leaves that turn to vivid scarlet in autumn. Mostly, though, the Rowans are small to medium sized at maturity, often with a rather slender, upright habit.
I’m a huge fan of autumn foliage colour. Over half of our entire garden is given over to autumn colouring trees, and Sorbus certainly contains some of the worlds finest. S. commixta, is one such, with leaves that consistently turn to burnt orange and glowing red in autumn. That species is another Chinese native, as is S. hupehensis, whose leaves have a distinct blue-ish cast, before turning deep red at the seasons end, as do those of the larger-leafed S. esserteauana.
As with all trees, autumn foliage colour can be inconsistent and short lived, dependent, as it it, on the vagaries of our climate, and most Rowans are undoubtedly grown primarily for their display of fruit. S commixta, S. esserteauana and S. sargentiana all produce berries similar to our native Moutain Ash, but the fruit colours within the Rowans extend well beyond fire engine red. Many of the Chinese species, including S. hupehensis, as well as S. forrestii and S. koehneana, bear white berries. S. cashmiriana has the finest berries amongst the white-fruiting species, with very large, marble-like fruit held in drooping clusters that remain on the branches long after the autumn foliage has fallen.
The newly introduced and highly desirable Sorbus rosea has gorgeous, large, clear-pink berries whilst those of S. vilmorinii start out rose red, slowly changing to pink and finally maturing to white flushed with apple-blossom, all against a back-drop of ever-intensifying red-purple autumn foliage.
It’s hybrid S. ‘Eastern Promise’ is similar but with larger berries that retain their deep-pink colouration throughout. Yellow-fruited Rowans are also available, including S. ‘Golden Wonder’ and the very famous, wild-collected S. ‘Joseph Rock’, which is a truly outstanding prospect when laden with it’s golden berries against a kaleidoscopic backdrop of red, orange and copper autumn foliage.





















































































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