Cornus sericea Seeds | Red Osier Dogwood
LATIN NAME: Cornus sericea
COMMON NAME: Red Osier Dogwood
Plant Profile
Red osier dogwood is a thicket-forming shrub of wet ground across northern North America, from Newfoundland to Alaska. It spreads by underground stems and by layering, and a single plant can cover several square metres in a few years. The leaves are opposite, oval and grey-green, with the veins curving towards the tip in the way that marks the dogwoods.
In late May it carries flat heads of small white flowers, and these become clusters of white berries in August. But the plant is grown for its winter stems: on young wood they are a clear, waxy crimson, brightest in full sun and on plants cut back regularly. Flaviramea is the yellow-stemmed form, and it is planted beside the red one for contrast.
Science & Biotechnology
The species is Cornus sericea in current use, though it was long known as Cornus stolonifera, the stolon-bearing dogwood, and the older name still appears in many floras. The genus has been moved around at family level: it sat in Cornaceae, was split into its own family, and molecular work has settled it back in Cornaceae but in a different position within the order.
The white fruit is a drupe, not a berry, and it contains a bitter iridoid that makes it unpalatable to people while birds take it readily. The red colour of the winter stems comes from anthocyanins that develop as the temperature falls, and they are strongest on one-year-old wood in full sun. The plant is a useful subject in wetland ecology because its roots bind stream banks and its thickets slow flood water.
Uses & Benefits
Red osier is planted for winter colour, for erosion control and for wildlife. On a stream bank its roots bind the soil, and its thickets give cover to small birds; in a garden it is used at the edge of a pond or in a wet corner where little else will grow. The stems are cut for winter arrangements, and they hold their colour indoors for weeks in water.
Cutting the plant hard in early spring, down to 20 centimetres, produces a crop of long, unbranched stems the following winter, which is how commercial growers get the bright material sold by florists. The white fruit is not edible for people, and the bark and leaves are mildly toxic. The Chinese medicinal fruit Shan Zhu Yu comes from a different dogwood, Cornus officinalis, and should not be confused with this one.
Growing from Seed
Cornus sericea is easy from seed if the fruit is cleaned and sown fresh. The drupes contain germination inhibitors in the pulp, so mash them in water, float off the skin and sow the stones at once in a moist mix. A cold period of three months at 4 °C improves uniformity; without it germination is spread over a whole season.
Cover the seed with five millimetres of compost and keep the pan in a cold frame. Seedlings grow quickly and can be potted on within eight weeks. Plant out in autumn in any soil, wet or dry, in sun or part shade, and cut the new plant to the ground after the first year to force it to sucker. To keep the stems red, cut a third of the oldest growth each spring; an unpruned plant turns dull brown and loses the effect entirely.
Our Take
The best red-stemmed shrub for wet ground, and one of the few that improves with hard annual cutting. Plant it where winter colour matters.
Related Reading
Gardeners who grow Red Osier Dogwood often pair it with these related subjects: