The Casual Gardener: Dogwood has the loudest bark
Dogwood bark is one of winter's great pleasures but that isn't this popular shrub's only selling point, writes John Manley
IF I'M honest I'd never even thought about the possibility of a native dogwood. I've certainly never consciously seen one in the wild.
Those eye-catching dogwoods that populate motorway embankments and roundabouts throughout Ireland aren't natives. They are cultivars – cultivated varieties – that have been bred, sometimes from the native but mostly from alien species, and their best assets enhanced – in this case brightly coloured bark, especially on young growth.
In fact I'd never really contemplated dogwood in the wild anywhere, until recently reading Bill Bryson's account of his hike along the US's Appalachian Trail. Dogwood seemed to crop up quite a bit in A Walk in the Woods – the woods in question being ancient North American woodlands whose flora is largely unchanged over millennia.
Perhaps if Ireland had more ancient woodlands I'd be more familiar with the native Cornus sanguinea.
Its Asian cousin Cornus alba and varieties derived from it are instead what we mostly see, but I'm not complaining. This deciduous shrub is among my top 10 favourite plants. It's unfussy, easily cultivated and maintained, and its bark blazes with colour when caught by the sun on a winter's day.
Cornus alba ‘Sibirica' – the Siberian dogwood – has arguably the brightest bark. Cut back each year as the previous season's growth is always the most vivid, the shrub forms a thicket of crimson stems and expands naturally by layering.
The coloured bark is the selling point for many dogwoods though not always in shades of red. Cornus sanguinea ‘Midwinter Fire' has orange-red stems while those of Corus stolonifera ‘Flaviramea' are yellow.
Those Cornus species and varieties that tend not to be prized for their bark colour have either attractive flowers or foliage. Those with the best blooms are Cornus kousa chinensis (white flowers), Cornus florida rub (rosy red flowers) and the taller Cornus mas, which reaches up to 10ft and bears masses of small gorse-like, yellow flowers in spring. For attractive foliage it's hard to go past Cornus alba ‘Elegantissima', which has white-edged leaves or Cornus alba ‘Spaethii', with its bright, yellow-rimmed leaves.
Propagation of the bark coloured types is relatively easy. You can either take cuttings – hard, softwood or semi-ripe – or less hassle is layering in situ, which involves pegging one of the flexible branches to the ground and leaving it a few months until it takes root.
Its easy propagation means I'm always alarmed when I see a potted dogwood for sale in a garden centre – usually priced between around £5-£10. Also, many Cornus are available bare root during winter, usually on sale at little over a pound.
Dogwoods are tolerant of most soils and prefer an open sunny site, which is where their stems will look best come winter. Because propagation is so easy, it's possible to group several of them together in clusters, making their display doubly effective. However, if planning to give contrast by planting a red-stemmed variety alongside a yellow or gold, it's recommended to keep them in matching groups rather than mixing them up.
As mentioned above, the key to getting a strong winter display from your dogwood is pruning, which should be carried out in spring. Pruning the stems back hard almost to ground level will encourage more new shoots to emerge, and these will grow 3ft-4ft over spring and summer. It is this fresh growth which provides the most vibrant colour the following winter.