On a bright winter’s day, the M1 motorway south of Dundalk to just north of Dublin offers one of the best displays of shrubbery anywhere on the island.
The eastern facing flank, which gets the most sun, is the best, alternate drifts of red and yellow last for miles, a pastoral scene incongruously lining one of our busiest roads.
The plant in question is dogwood. The red is probably Cornus alba, the yellow (or is it a bright green?) most likely Cornus stolonifera flaviramea.
There are some dogwood cultivars treasured for their foliage but it’s a shrub that without doubt looks its best when naked. The youngest stems are the brightest, which is why it’s best to hard prune every spring, encouraging fresh growth.
The dogwood adorning the motorway verges disappointingly are not the native Cornus sanguinea – or conbhaiscne, as Gaeilge – which is found typically in hedgerows and on woodland peripheries.
It’s a plant with an unsettling mythology. According to legend, Jesus Christ was crucified on a cross made from a dogwood tree – though the Bible doesn’t specify the type of wood used.
It’s said that as a result God cursed the dogwood tree, decreeing that it would never grow large enough to be used for another crucifixion.
The myth doesn’t withstand much scrutiny, however, as the dogwood is not native to the Middle East and would not have been readily available in AD 33 Palestine.
Moreover, in some cultures and religions dogwood has strong associations with Easter.
The plant has a number of characteristics that symbolise the crucifixion and/or Christianity – its flower, which will only appear in spring on non-pruned branches, has four petals, making the shape of a cross; the centre of the flower resembles the crown of thorns, with the deep red, clustered fruit in the middle representing the blood of Christ.
Cornus alba ‘Sibirica’ – the Siberian dogwood – has arguably the hottest red bark, forming a thicket of crimson stems if pruned annually.
Cornus sanguinea ‘Midwinter Fire’ has orange-red stems, while those of the aforementioned Corus stolonifera ‘Flaviramea’ are prized for their vibrant yellow bark.
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.
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.
If planning to create an M1-style contrast by planting a red-stemmed variety alongside a yellow or gold, keep them in matching groups for the strongest display rather than mixing them up.
