Ribes sanguineum Seeds | Flowering Currant
LATIN NAME: Ribes sanguineum
COMMON NAME: Flowering Currant
Plant Profile
Among the packets the Scottish collector David Douglas sent out of the Pacific Northwest in the 1820s was the seed of a currant whose long hanging trusses outred every hardy shrub then in cultivation. British nurserymen raised it quickly, and the flowering currant has been a fixture of temperate gardens ever since, prized as much for opening its flowers on bare wood as for the colour itself.
The shrub is deciduous, upright when young and then arching, and it carries alternate, five-lobed leaves on a network of pale shredding bark. Every part of the leaf surface, and especially the underside, is set with stalked glandular hairs that release a sharp resinous smell when brushed. That stickiness marks the species on a summer walk, and it is why the coastal form was once separated as the variety glutinosum, on the strength of its denser glands and paler flowers.
Flowers are held in drooping racemes that can carry thirty small tubular blooms, each with five petals and a nectar disc at the base of the tube. Crimson is the commonest colour in the wild, pink in the coastal populations, and a white form appears now and then. The tube is deep enough to exclude short-tongued insects, and in its native range the rufous hummingbird is the pollinator that matters; in a European garden the shrub is worked instead by early bumblebees, which bite through the base of the tube to reach the nectar.
The fruit is a small globose berry, black at maturity and dusted with the waxy bloom that gives it a blue-grey haze. Each berry holds a few seeds and the flesh is thin and seedy, so the crop is worth more to thrushes and blackbirds than to a kitchen. Where the shrub is left unpruned, birds strip the fruit and scatter the seed, and the species turns up along hedgerows and fence lines well beyond the garden that planted it.
Science & Biotechnology
The leaf glands that make the shrub so aromatic are capitate trichomes on a short stalk, and the resin they secrete is dominated by monoterpene hydrocarbons, with pinene and limonene among the chief volatiles. Work on the essential oil of the genus treats that resin as the source of the pungent top note which divides gardeners into those who like flowering currant and those who plant it at the far end of the plot. The same resin makes the shoot tips unpalatable to most browsing mammals. Ribes sanguineum carries sixteen chromosomes in its diploid complement, the number shared by the great majority of currants and gooseberries, which is one reason the species crosses so readily with its relatives in breeding programmes.
Two research lines keep this species in the literature. The first is micropropagation: Ribes clones are multiplied on agar media from axillary buds to produce clean planting stock, and the protocol runs well on flowering currant. The second concerns Cronartium ribicola, the rust fungus that alternates between five-needle pines and members of this genus, killing white pines while the currant host merely tolerates it. Screening of New World Ribes, this species included, has formed part of the search for resistance that might be moved into the pine timber lines.
Uses & Benefits
Plant the flowering currant where winter and early spring sun reaches the wood, because the flowers open before the leaves and shade delays them. It makes a serviceable informal hedge at about two metres between plants, and it will hold a coastal bank where salt wind discourages other shrubs. The berries are edible but thin-fleshed, so cooks add sugar and a little lemon, or blend them with apple, since the resinous taste grows stronger when the fruit is cooked alone. In a wildlife garden the shrub earns its place twice over, first with early nectar and then with fruit that feeds migrating thrushes.
Growing from Seed
Flowering currant seed is small and flat and carries a natural dormancy that a moist cool period breaks. Sow it in a pot of loam-based compost mixed with an equal part of sharp sand and a little leaf mould, press the seed onto the surface, cover it with about three millimetres of sieved compost and stand the pot in a shaded frame outdoors so the weather can work on it through a winter. Once seedlings carry four to six true leaves they can be pricked out into individual pots, and a plant given a two-litre pot will establish without a check if it goes into the ground in autumn.
Set a specimen shrub about two and a half metres from its neighbours and a hedging line closer, then water steadily through the first summer; after that the plant tolerates dry spells once its roots reach down. Feed lightly in spring with a balanced fertiliser rather than a rich one, which encourages soft growth at the expense of flower. Prune straight after flowering by cutting a third of the oldest stems to the base, because next season’s bloom comes on young wood, and never shear the shrub in winter. The commonest complaint is the currant blister aphid, which raises red puckers on the upper leaf surface and shelters beneath; the damage is cosmetic, and a hard spray of water or an early soap treatment is enough.
Our Take
Grow this shrub for its trusses and give it a companion that also flowers on bare wood: Corylopsis sinensis opens at the same moment, and its scent carries further on a still morning. Berries are the second reason to keep a flowering currant, and anyone who wants a fruiting hedge should look at the honeyberry, Lonicera caerulea, whose crop ripens far earlier in the season. For winter colour of a different kind, plant the red-stemmed Cornus sericea behind it, where the bare currant wood will not hide the stems.
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