There are over 45 species of Cornus, but those which which produce the brightly coloured winter stems are C. alba, sanguinea, and sericea, all of which are commonly called Dogwoods.
Dogwoods are deciduous shrubs, with attractive variegated foliage illustrated above left. The leaves turn a stunning red in autumn as shown in the centre image, and the stems provide strong winter colour, image right.
We cultivate dogwoods for their colourful winter stems, in shades of bright red, yellow, orange, throughout the winter.
To get the best effect, plant a group 3/4/5+ together. To show off the coloured stems at their best plant Cornus where they will be back lit by the low winter sun, or the sun will strike the red stems.
Cornus is really easy shrub to grow and fully hardy H7 which is down to -20. Because it is so vigorous, it is not necessary to run to the cost of mature shrubs. Cornus will grow quickly and cheaply from whips, (more below.)
The only downside to coppicing Cornus is that shrubs with variegated foliage are prone to revert. It's a balance whether you grow Cornus for the winter colour, or variegated foliage.
Popular are: Cornus alba 'Sibirica', illustrated right, which has strong red stems, C. sanguinea 'Midwinter Fire' which has orange stems and Cornus sericea 'Flaviramea' with yellow stems.
This group of Cornus will grow in any type of soil, in sun or partial shade, although to get the best winter stem colour grow in full sun. Dogwoods are a tough, grow anywhere shrub and this includes moist and damp soil. They are commonly seen in semi wild conditions growing alongside brooks and streams where the soil is damp. I have some growing alongside a stream in very boggy conditions. I have also seen them growing well in supermarket landscaping on poor soil and with little or no attention, and still looking good.