Large bunches of big black currants, rich in flavour, command fantastic prices even in the cheapest times; which is only one reason why a few bushes should figure in every bit of private ground where room can be found, or made, for them. The fruit is always in demand for pies, puddings, wine, jelly, jam – the latter an old-fashioned but sound remedy for sore throat.
Ready for Use. First black currant pickings are made in July, and the season extends into September.
Varieties include, in order, approximately, of ripening: Boskoop Giant, Raven, Davison’s Eight, Seabrook’s Black (less prone to big bud trouble than most others), Victoria, Edina, Baldwin, Daniel’s September.
The black currant is available in bush form only; its fruiting habit renders it unsuitable for training otherwise.
A dry root-run has to be avoided. Any ordinary fertile soil will produce good crops so long as water can be given in dry summer spells. The ground should be dug 12 in. to 18 in. deep and rotted manure mixed in freely, or leaf-mould or decayed weeds; this is specially necessary if the ground is sandy or thin.
When and How to Plant.
As soon after the leaf-fall as possible is the best planting time, though bushes may be got in throughout the winter when the ground is not very wet. Planting should not be attempted in periods of snow or frost.
A sunny, sheltered spot is appreciated. The bushes should be set out 4 ft. apart, a little deeper than the soil mark on the stems, and the soil should be firmed around and above the covered-in roots by treading.
Either before or just after planting the young bushes should be cut down to within about 5 in. of the ground. This means a total loss of fruit the following summer; but the plants gain strength, and without the burden of having to support much top growth are able to build up a sturdy root system. Plenty of fruit will be produced the year after and subsequently.
The best fruit is carried on young shoots which were produced during the preceding summer. Older wood will also fruit, but the pruner’s aim is to get rid each winter of as much of the old wood as can be replaced by existing strong new growths. The old wood should be cut out, after the fruit has been gathered, as low down as possible. The result of this treatment is a more or less new black currant bush for the following year’s fruiting. An open centre is maintained by making all cuts back to buds which point outwards.
Watering and Feeding.
First-year plants are in particular need of water during a dry spring and summer – a bucketful per bush, poured on to the soil after the surface has been loosened with the hoe. The soil should always be kept stirred around the plants, but neither spade nor fork should be used or the shallow roots will suffer; the hoe is the tool to use. A surface covering of rotted manure put down in late spring is excellent. This keeps the soil moist, and provides food when water is given through the rich mulch.
The mites that cause some buds.of black currant to swell abnormally are tremendous little pests. This big-bud trouble is noticeable in winter, mite-infested buds being double the size of normal ones and round in shape; unattacked normal ones are long and pointed. There is no possibility of mistaking buds which the microscopic mites have occupied.
Undersized, crumpled leaves may be produced by these buds, or the latter may dry up and perish during early summer. The trouble becomes worse each year, until the bush is fit only for the bonfire. The way to fight it is to pick off all abnormally swollen buds in winter and burn them; and then, before flower buds are open and when leaves are about the size of a shilling, spray the bushes with lime sulphur solution. This is made by mixing J pint of lime sulphur, purchased from a garden supply shop, with 3 gal. of water.
The solution is to be applied as a very fine spray so that upper and under sides of leaves and all the wood are wetted. This catches the mites when they are on the move to other and so far healthy buds.
Birds and Caterpillars.
If caterpillars are troublesome they can be got rid of by dusting or spraying the foliage with Derris insecticide just after flowering.
To keep birds from sampling the fruit, a persistently active dog or cat is invaluable; otherwise old fish netting, or discarded muslin curtains, should be draped over the bushes after the black currants have finished flowering.
A cold spring may render bees so inactive that only an odd insect or two may crawl about the flowers and so effect transference of fertilizing pollen. The setting of the fruit is not entirely dependent on visits of bees and flies, but when insects are not active at flowering time the trusses of fruit may be very poor indeed. Unfortunately, nothing can be done about this.
When black currant bushes flower well yet fail to produce fruit, and neither big-bud nor a cold spring is to blame, it is almost certain that the unfruitful bushes are victims of a disease known as reversion or nettlehead. Not all shoots on a bush will be affected at once, at the beginning. But the disease spreads, until after a couple of years or so the attacked bush is incapable of producing a berry.
Obvious signs that reversion is to blame appear in the leaves of attacked shoots, these leaves being narrower than normal ones and with fewer indentations of the edges. Also, side shoots with narrowed leaves are sometimes produced in a cluster, giving the effect of a bunch of nettles. These bushes should be dug up and burned.
Black currant bushes are easily increased by means of cuttings taken during September or October, from thoroughly sound bushes only.
Gathering the Fruit.
Picking should begin as soon as there are enough ripe berries available and continue, at intervals, until the bushes have been stripped. Bunches – or strigs – are taken complete, to save unnecessary handling of the fruit, which bruises very easily.