I can remember sitting on long summer afternoons, dipping bunches of red and white currants first in a little white of egg and then shaking them in a bag with some caster sugar to crystalise the fruits. The bunches were allowed to dry and were then eaten as a special treat the next day, a most delicious way of serving them.
Of the three kinds of currants, black currants derived from Ribes nigrum are grown more commonly than red currants (derived from the inter-crossing of three Ribes species) or white currants (derived from red currants). All three are selffertile, fruit prolifically and take up only a relatively small area. They all thrive in most districts and start cropping early in life (for ornamental currants see Ribes).
No soil is too rich for black currants; they can be fed lavishly with nitrogenous fertilisers. They prefer soils with good drainage but retentive of moisture—black currants will absorb copious amounts of water. Poor growth on thin soils can be improved by applying deep mulches.
Red and white currants withstand drought better than black currants and are less greedy for nitrogen. Otherwise, their requirements are very similar. Red and white currants blossom early and so must not be planted in low-lying frost pockets. Black currants tolerate being partially shaded by trees or buildings though this delays ripening a little. A sheltered site is desirable to encourage pollinating insects to work if flowering time coincides with bad weather. The bushes have a productive life of up to twelve years.
Black currants are in season from July to early September, fruiting on the previous season’s shoots. Red and white currants ripen from late June to late July and fruit on spurs fomed on the old wood. Cultivation
The modern method of planting black currants is to insert three cuttings 4 inches deep at each planting position and allow them to fruit in situ. Plant at 6 x 3 feet intervals. Cuttings 12 inches long, are taken in the autumn from well-ripened shoots of the current season’s growth—it is unnecessary to make the cuts directly below the nodes as the cuttings root readily wherever the cuts are made.
Alternatively, plant one to two-year old bushes between October and mid-March, the earlier the better. The soil should be dug deeply prior to planting and have 1 cwt of well-rotted farmyard manure dug in every 10 square yards. Do not allow the fibrous roots to become dry while awaiting planting; heel them in until planting can be carried out. The roots should not have more than 2 inches of soil above them when planted in their permanent positions.
Cuttings rooted in situ can be allowed to fruit the first season but transplanted one-year-old bushes should be pruned to help them recover from the transplanting check and induce strong growth, by shortening the shoots to four buds.
Feed black currants in the spring with 2 oz per square yard of sulphate of am-monia or Nitro-chalk and in the autumn with 1 oz per square yard of sulphate of potash. Red and white currants manage with 1 oz of sulphate of ammonia per square yard in the spring and the same amount of potash in the autumn.
Generally, red and white currant bushes are grown with a short leg, 4-5 inches in length, sucker growths being removed; on dry gravel soils, die back may be severe and a multi-stemmed bush may be more practical. Bushes with a leg are obtained by first removing the buds from the bottom half of each cutting before insertion.
Single or double cordon red or white currants, planted against a wall, give extra-large berries and are easily netted against birds. Plant bushes 5 feet x 5 feet, single cordons 1 foot apart in the row, double cordons, feet apart in the row; rows 4 feet apart.
Prune red currants in the winter by shortening the leading shoots by a third and the sideshoots to two or three buds. Summer pruning in July promotes fruit bud formation. Shorten the sideshoots to five leaves; leave the leading shoots un-pruned.
These are grown as stools after planting. Young plants raised from cuttings are cut to 2-3 buds from ground level after planting. The shoots which grow in the first summer will fruit the year after. In succeeding years pruning, which can be hard or light depending on growth, aims to keep-up a supply of new shoots. This will mean the cutting out of a proportion of old, unfruitful wood (and some young shoots). Prune the older shoots as close to ground level as possible. It is possible to grow plants against a framework and the techniques are the same as for bushes but the branches are tied to suitable supports. Pruning should be done as soon as the fruit is picked or in winter.
These currants can also be trained as cordons with one, two or three branches. The shoots from the young plants are trained to a suitable framework. The leader is pruned hard, removing half to two-thirds of the length until the required height is reached. Laterals in the mean-time are pruned to 1 inch from the main stem to form spurs which are thinned out from time to time. Height it is pruned above a good bud to begin the branch system the following year. It may take three to four years before a main stem framework branches are made, especially with weak varieties. The pruning of the head of the standard thereafter follows the same lines as a bush. Greater care should be taken to avoid overcrowding of branches especially with vigorous varieties. Staking should be done early, as the plants may in time become top-heavy. It may be possible to purchase standards grafted on the sturdier Ribes aureum as the rootstock.
Red and white currants
Young plants from the nursery are usually 2-3 years old and the main branches are already formed on a short leg. After planting the leading shoots are pruned by half to two-thirds depending on vigour. The laterals, or side branches, are pruned in winter to 1 inch from the main stem. From time to time old branches can be replaced by new growth lower down. Resist the temptation to keep too many shoots in the mature plants, 8-12 should be ample. Fan-shaped bushes are also useful. The five or six branches from young shoots are spread on a suitable support and trained as cordons.. Should you find that your black currant bushes are not cropping as they should it may be that they are infested with big bud.
Standard red currants and goose-berries
One -year-old plants from the cutting rows can be trained to make standard bushes with a main stem of 2 I-3 feet. One shoot, usually the topmost, is retained and encouraged to grow upright to form the main stem. At the desired This condition of black currants is caused by the activities of microscopic gall mites, Phytoptus ribis. If a swollen bud is cut open and examined under the microscope hundreds of elongated mites, less than one-hundredth of an inch long may be seen.
They live and breed in the buds from July until spring when they migrate to the leaves and blossom until the new buds are formed and they can inhabit them.
In light infestations, the swollen buds may be picked off and burned and the bushes sprayed annually with lime sulphur. This should be done in late March or early April when the blossom trusses resemble small bunches of grapes. Use 2 per cent lime sulphur a pint in 3 gallons of water), and three weeks later spray again using 1 per cent lime sulphur (I pint in 3 gallons of water).
Severely infested bushes should be burned. There is a risk of the pest spreading the disease known as reversion.
Red currants and gooseberries are also attacked by the mite but do not exhibit swollen bud symptoms.
I remember how interested I was when I first saw black currants being grown on a commercial scale to see the quantities of rich compost mulch heaped around the base of each bush. An amateur does not always readily understand how important it is to feed plants.
- How much fertiliser, what kind, when to apply and where to apply are the questions we now have to answer in order to get the best results from our fertilisers. But this is no easy matter to solve; there is no indicator that you can push into the soil or fasten on to the plant that will tell you whether it is hungry or not. If only plants squealed like pigs when they are hungry it would be a much easier task for us.
- The feeding of plants is still a matter of intelligent guesswork with the aid of a little science.
- The plant reflects the level of nutrition in many ways. The type of growth, the colour of the leaves and yield are obvious indications of soil productivity. Plants develop characteristic symptoms when they are poorly nourished. Many of these deficiency symptoms have been recognised and described for all the essential elements for many plants. Deficiencies are easy to see, but not so simple to identify since several may show the same symptoms. There are many other things that can cause poor plant growth; the weather has a great deal to do with it; if the weather is cold and wet plants will make little progress. Poor drainage can produce symptoms like those of nitrogen defici-ency; wind scorch often looks like potash deficiency.
- By the time symptoms are shown the plant is suffering from acute hunger and it is often too late to correct the trouble.
- Prevention is always better than cure and you should always make sure that deficiencies are corrected before sowing by having your soil tested. Then fertilisers can be used to compensate for the missing nutrients.
- Sometimes, even though a plant may look well, it can still be suffering slightly from a lack of certain nutrients; this is known as ‘hidden hunger’ and it will respond greatly to a fertiliser dressing that contains the food of which it makes extensive use. For instance your cabbage may be doing nicely, but they would do much better if nitrogen were added.
- Three things must be done should your plants be suffering from the lack of certain nutrients. First, find out what ails the plant, I.e. diagnose the deficiency. Second, try to find out how serious the deficiency is. Third, determine, as nearly as you can, how much of the missing nutri-ent is needed to bring the plant back to health.
- Chemical soil tests may help to pinpoint the trouble. Another way is to diagnose the trouble as closely as possible, then spray the foliage with a foliar feed. If the plants show marked improvement within two weeks you are on the right track. Continue to apply fertiliser every two weeks until the plant resumes vigorous growth.
- It is possible to let the plants speak for themselves by carrying out a chemical test on the leaf; this is known as tissue testing — a valuable tool in the hands of one who understands soils, fertilisers and plant growth but one which can lead you to apply fertiliser that is not needed and will not help your crop. A more refined method known as leaf analysis is used for guiding fertiliser programmes in fruit and other perennial plants.
Methods of feeding with fertilisers
- If new beds or borders are being prepared fertilisers are best scat-tered evenly all over the ground after digging. Then mix with the top few inches of soil by raking, lightly forking or with a rotary cultivator.
- This is best suited to the crops that you sow in shallow rows or plant closely.
Banding along the row
For peas, beans and other vegetables that are sown in widely spaced rows the best place to put the fertiliser is in a band 1 to 2 inches to the side and 1 to 2 inches below the depth of the seed by hoeing out a trench. The roots of the young plant contact the fertiliser within two or three days after the seed germinates and get a big enough ration of food that will last annual plants for quite a long time. But never scatter fertilisers down the seed drill because they will injure most vegetable and flower seeds.
Dilute liquid feeds may be watered on to drills, seed trays of plants or potted plants before planting to give a rapid start.
Putting fertiliser along the rows after the plants have started growing is often done to add some extra nitro-gen. You are most likely to need to top dress under these conditions:
- On sandy soils and thin chalky soils because leaching is common.
- After heavy rains have washed out nitrates.
- On soils that are low in organic matter.
- Where you have not given enough Nitrogen when you planted.
This is the best way of feeding perennial plants growing in borders, established lawns, fruit trees, roses and shrubs. The fertiliser should be spread as far as the branches reach to contact the actively absorbing root hairs.
- To apply fertiliser in perennial borders, spread a small handful in a wide ring around each plant and mix carefully with soil. Either solid or liquid feeds are suitable for these dressings.
- Liquid feeding Liquid feeds which are merely fertilisers in solution, are often more convenient to apply, particularly in crowded borders where it is difficult to spread a solid fertiliser without getting it on the foliage.
- The foliage of many potted plants com-pletely covers the surface of the pot and feeding with solid fertilisers can be hazardous. With liquid fertilisers feeding and watering is done in one operation—a distinct advantage when you have large batches of pots to look after.
- Liquid feeding is essential if you intend to use drip irrigation in which the water issuing from nozzles gently trickles into the soil and spreads sideways underneath, leaving the surface dry.
- Feeding through the leaf. It is not only roots which can absorb plant foods but the foliage also can absorb nutrients very quickly thus short circuiting the long journey from the roots. Although it is unlikely that this method will supersede normal soil applications, it has ad-vantages.
Obviously the above comments are very general: soil conditions and the needs of the individual plants will determine which and how much fertiliser to use. It must be stressed however, that fertilisers merely supplement the soil’s store of nutrients.