Winter's low and golden light reveals the charms of bare trees, writes Jane Powers
There are few gardening disasters that can't be turned around if you apply the proper Pollyanna spirit. So when a September gale ripped one of the trunks off a tristemmed purple hop bush (Dodonaea viscosa 'Purpurea') in our garden, it didn't take me long to see the bright side. What had been a neat teardrop- shaped shrub 10 years ago had grown into an obese blob of a bush, requiring annual pruning to keep it from overflowing all over the place. The autumn storm cleanly removed a vertical slice of its bulk, simultaneously trimming off kilos of excess foliage and revealing a cross section of its woody structure. With a little additional secateur work, to snip off the lower branches, it was transformed from fat-bellied shrub to airy little tree. But the best thing about the metamorphosis is that this Australian native's peeling caramel bark - once hidden by a mass of bronze, evergreen leaves - is now on show, catching the low winter sun and warmly reflecting its rays.
The next couple of months are the season for branches and stems to take centre stage in the garden. With not much going on in the flower and foliage departments, there is little to distract from the quieter presences of bark and twig. And the light, being low and golden, is perfect for enhancing their woody charms.
Birch is the classic winter "barker", with its conspicuous trunks and dark maroon twigs - which look magical when spangled with raindrops. Among the many white and chalky birches are Himalayan birch (Betula utilis var. jacquemontii and its cultivars) and paper birch (B papyrifera). Silver birch (B pendula) is also white-trunked, although the base becomes darker with age. 'Tristis' and 'Youngii' are the more readily available ones, with the latter better suited to smaller gardens. The bark on most pale birches responds very well if you have a go at it with a stiff scrubbing brush and a bucket of water. This removes the build-up of dust and algae, and restores the chalky sheen.
The Betula genus, which occurs right across the northern hemisphere, has many members with bark in colours other than white.
B albosinensis, the Chinese red birch, has a pink or copper peeling skin; B nigra, the river birch, is dark and shaggy; and B ermanii is a creamy pink that is most pronounced when the new bark is revealed. Birches, especially the paler kinds, associate beautifully with low, white or blue spring bulbs, such as crocus, scilla and chionodoxa.
One of the richest-toned barks is that of the Tibetan cherry, Prunus serrula, a smallish tree with a shining, mahogany surface that house-proud gardeners sometimes buff with a cloth, to bring up the lustre. Other, less common cherries with barking good trunks are the Manchurian cherry, P maackii; the Himalayan cherry, P rufa; the Chinese P canescens; and the hybrid P x schmittii.
Acer griseum, the paper bark maple from China, is clothed in a filmy, peeling sheath of vibrant copper. The tree is slow-growing, but the trunk begins to unravel as soon as it achieves the girth of a broom handle. Of all the trees with show-off bark, this one demands a position where the sun can shine through its unfurling tissue-paper frills, making it glow with a fiery halo. Add to this its excellent autumn colour, and you get an energetic, blazing presence: a pagan tree god that you must pay homage to.
The snakebark maples are in sleek contrast to their shaggy cousin. Their olive-green, brown or reddish skins are as sinuous and close-fitting as those of the reptile whose name they take, and are hand-painted with exquisite silvery, pale-green or rusty lines that become more obvious after frost. Younger limbs have finer markings, as the definition becomes coarser as the branches age. Most of the snakebarks are from Asia: A davidii, A forestii and A grosseri are from China; and A capillipes and A rufinerve are natives of mountainous areas in Japan. North America gives us A pensylvanicum, which grows in damp woodlands in the eastern states.
The slim stems of dogwoods and willows have become a familiar sight along the motorways, creating brightly pencilled sketches in red, wine and lime green. The richest winter colour is seen on the stems that are less than one year old - so annual pruning is a good idea. You can either take the whole shrub down to a few inches from the base each spring (and give it a thorough watering, and a feed of manure or other fertiliser to boost it back into growth) or just take out the the duller stems every year. Even pruning drastically every second year ensures that these fast-growing twiggy plants continue to look lively.
Among the many dogwoods adapted for such treatment are Cornus alba 'Sibirica' (bright red stems), 'Elegantissima' (wine stems with grey-green and white variegated leaves), 'Kesselringii' (purple-black stems); and
C sericea 'Flaviramea' (yellow or green stems). Suitable willows include Salix alba 'Britzensis' (scarlet-orange), and S daphnoides (dark and plummy). Don't be too eager to throw out the colourful prunings: they are easy to propagate (cut into 20-30cm lengths, shove into the ground and forget about them for a year). Or stick them into flower arrangements, or use as plant supports.
Another plant genus that provides light-catching winter stems is Rubus, whose members include the bramble and raspberry. The Chinese species, R cockburnianus and
R thibetanus, have gleaming, white-dusted, arching stalks, which earn them the name of "ghost brambles" in the US. Their thorns can be anything but ghostly, however, so they need a large garden, and a space to call their own. Annual pruning is essential if you don't want an impenetrable bramble patch - Chinese or not.
So far, all the plants I've mentioned are deciduous (except for the Dodonaea that started this whole train of thought). But there are plenty of evergreen shrubs and trees whose trunks and branches become horticultural eye candy when they are hit by winter's low rays. Our native strawberry tree, Arbutus unedo, has rather quiet, brown, shredding bark, but its Greek half-sibling A x andrachnoides is wildly boisterous, with a cartoonish, splotchy wine-and-crimson covering.
Myrtle (Luma apiculata), a native of Chile, has beautiful cinnamon-coloured limbs and branches. It is a little tender in cold gardens, but in Cork and Kerry it has made itself at home and become naturalised.
Various Rhododendron species have arresting bark, ranging from pinky-brown to deep wine. All need acid soil, as does Stewartia pseudocamellia, another woodland tree with handsome bark.