Cornus sanguinea Seeds | Dogwood
LATIN NAME: Cornus sanguinea
COMMON NAME: Dogwood, Bloodtwig Dogwood, Common Dogwood
Plant Profile
The winter colour comes from the youngest wood. The previous season’s shoots, and especially the long whips thrown up after hard cutting, carry the deepest red, and the side of the stem facing the sun is always the more strongly coloured. Old, thick stems go brown, which is why a neglected bush is dull in winter and a regularly cut one is not.
The red is anthocyanin, cyanidin-based pigments built up in the outer tissues of the shoot as the temperature falls, and the same pigment group colours the autumn leaves before they drop. The shift is an investment rather than an accident: the plant is protecting young tissue through the cold, and in a hard winter the colour is deepest on an exposed, sunny stem.
A dogwood leaf is easy to know by its veins. The lateral veins leave the midrib and curve forward towards the tip without reaching the margin, so the leaf looks ribbed or pleated; botanists call this arcuate venation, and it runs through the genus. The leaves here are opposite, oval and pointed, turning to dull reds and purples in autumn.
The fruit is a small black drupe carried in loose clusters, and it is not a pleasant mouthful. Split one and a white latex appears in the flesh; the taste is bitter and drying, and the fruit works as a purgative rather than a food. That is one explanation for the English name dogwood, that the fruit was fit for nothing, though the older suggestion, that the name descends from a word for a pointed skewer cut from the wood, is as good.
Before cheap lamp oil, a hedgerow that produced oil was worth having. The drupes were crushed and pressed in parts of Europe, and the oil that came off was burned in lamps, a small homely industry built on a fruit that could not be eaten. The same fruit gave a dark dye.
Science & Biotechnology
The bitterness belongs to the bark as well, where the iridoid compound cornin, also called verbenalin, sits alongside tannins. Iridoids of this type are a chemical signature of the genus, and they are the reason dogwood bark was a bitter tonic in European practice. The birds that eat the drupes are unaffected, which is how the species spreads along a lane.
Uses & Benefits
A dogwood stool cut to the ground will throw long, straight, flexible shoots in a single season, and those shoots were the plant’s working value. They went into baskets, into the hoops of small barrels and into the binders that hold a newly laid hedge down along its stakes, because a dogwood withy bends without snapping.
For the garden the rule follows from that. Cut a third to a half of the oldest stems hard to the base in early spring, on a rotation so that some whips are always one season old, and the bush will colour every winter. Leave it alone and the red fades within a handful of seasons.
Growing from Seed
Dogwood propagates easily from hardwood cuttings, but laboratories also use nodal culture: explants carrying an axillary bud will break on a salt medium with a cytokinin and multiply into plantlets that can be rooted and hardened. These cultures have been used to follow how anthocyanins and iridoids accumulate, work with a practical edge for a plant whose ornamental value is the colour of its bark.
Clean the softened pulp off the stones and sow them in a gritty mix, pressed in about twice their own depth, and leave the pan outdoors through the winter: dogwood stones are hard-coated and the cold does part of the work. Sow more than you need and keep the pan shaded.
Move the seedlings on at three to five true leaves into individual pots, then plant them out in autumn or early spring, 30 to 45 centimetres apart for a hedge or a metre and a half apart as specimens, in sun or light shade and in any reasonably moist soil, including chalk. Water through the first summer, keep grass clear of the base, and cut the leading shoots back after planting to force branching low down. Aphids gather on the soft tips in early summer and are usually cleaned up by predators; leaf spot in a damp year is dealt with by clearing the fallen leaves.
Our Take
If the winter stem is what you want, the white dogwood (Cornus alba) gives you the same trick in several colours, and the red osier dogwood (Cornus sericea) is the North American equivalent that will take wetter ground. For a tree-sized dogwood with tiered branches, the pagoda dogwood (Cornus controversa) is the one to look at.
Related Reading
Gardeners who grow Dogwood often pair it with these related subjects: