Cornus alba 'Sibirica'

Cornus alba 'Sibirica'

The brightest of a colourful bunch of dogwoods grown for winter effect, ‘Sibirica’ has brilliant crimson stems, particularly bright when cut back regularly. The effect is enhanced at Rosemoor by underplanting snowdrops, (Galanthus ‘Atkinsii’, with its excellent glaucous foliage is very effective), or surrounding it with gold or silver variegated euonymus. ‘Sibirica’ thrives in our heavy, wet soil, and makes an excellent feature in the Winter Garden and around the Lake.

Vital statistics

Common name

Siberian dogwood

Family

Cornaceae

Height & spread

2m (6ft 6in) high and wide

Form

Vigorous deciduous shrub

Soil

Any

Aspect

Winter stem colour best in full sun

Hardiness

Hardy throughout the British Isles

Cornus

The dogwoods, Cornus, comprise a small genus of around 45 species of mostly deciduous shrubs and small trees from northern temperate grasslands, woodlands and swamps. Cornus alba was introduced from Siberia in 1741 though it also grows in China.

The genus Cornus is so named as it is the Latin name for the cornelian cherry, Cornus mas, grown for its colourful yellow flowers produced in spring, followed by bright red, fleshy, edible fruit in late summer. It also produces a wonderful autumn display with the dark green leaves turning reddish purple.

Cornus alba 'Sibirica'

Cornus alba 'Sibirica' is a deciduous, upright-growing shrub with dark green leaves which bears clusters of small white flowers in spring and early summer, followed by small white berries. It is most commonly grown for its brilliant crimson stems, which are at their best on sunny winter days.

The stems are most brightly coloured on the previous summer's growth and gradually darken as spring approaches. It is sometimes found under the name 'Westonbirt'.

Cultivation

• Cornus alba will grow in any soil, moist or dry, but for the best winter stem colour a moist site in full sun is recommended.
• Hard annual pruning produces the best display of colourful winter stems, but at the expense of flowering growth. However, allow plants to grow unpruned for the first year after planting. Prune in early spring, before bud break, by cutting back all the stems to within 5cm (2in) of the ground, or within two buds of the previous year's growth.
• Neglected plants can be renovated by cutting out the old wood at the centre of the bush.
• Cornus are rarely affected by pests and diseases, though some may suffer from cornus anthracnose. This fungal infection is most prevalent in cool, damp weather, with infections showing as spots appearing on the leaves in late spring or early summer. As the infection develops patches of dieback may appear and in severe cases the plant may die. Cornus alba can be affected but only the weakest shoots tend to die while the rest of the plant remains healthy. To stop the infection spreading the affected branches should be pruned out and burnt.

Propagation

• Softwood cuttings should be taken in summer
• Alternatively, hardwood cuttings can be taken in autumn or early winter

AGM

The RHS Woody Plant Committee awarded Cornus alba 'Sibirica' an Award of Garden Merit and described it as a:

"Medium-sized suckering deciduous shrub forming a thicket of slender red stems, becoming bright crimson in winter. Leaves ovate, flowers small, cream, in flat heads; berries bluish-white."