Black Currant Cultivation – Varieties, and Planting
Black Currant Cultivation
The Black Currant (Ribes nigrum) is also called Blackcurrant or cassis. Black Currant belongs to the family Grossulariaceae grown for its edible berries. It is widely cultivated both commercially and domestically. It is a small hardy attractive deciduous shrub that fruits in early summer. Currants are woody and perennial shrubs and are best known for their tart fruit. Plants are hardy, self-fruitful, and tolerant to partially shaded sites.
Black Currant is winter hardy, but cold weather at the flowering time during the spring can reduce the crop size. Though, bunches of small and glossy black fruit develop in the summer season and can be harvested by hand or by machine. The raw fruit is mainly rich in vitamin C and polyphenols. These fruits can be eaten raw, but are usually cooked in sweet or savory dishes. Then, they are used to make jams, preserves, and syrups and are grown commercially for the juice market. Also, the fruit is used to make alcoholic beverages and dyes. These are very easy-to-grow bushes that produce bunches of dark purple to black fruits.
Black Currant Cultivation – Varieties, Propagation, Planting, Training, Pruning, and Care
Growing Black Currant
Different Varieties of Black Currant
Baldwin – It is an English currant variety that is very productive with medium quality fruit and highly susceptible to White Pine Blister Rust.
Ben Lomond – Having excellent fruit quality and production and slightly susceptible to White Pine Blister rust and powdery mildew.
Ben Nevis – It is having excellent fruit quality and high production. It is slightly susceptible to White Pine Blister Rust.
Ben Sarek – It is excellent fruit quality and not susceptible to White Pine Blister rust and powdery mildew.
Blackdown (Black) – It is an upright, disease-resistant shrub that produces large, black, musky fruit ideal for jelly and juice. The fruits are ripe in July.
Consort – It is Canadian variety and immune to White Pine Blister Rust, slightly susceptible to powdery mildew and excellent fruit quality and production.
Crusader –Bears large fruits in loose clusters. Produces good yields of dark blackberries and needs another variety for pollination and carries a dominant gene for rust immunity.
Minaj Smyriou – It is a Heavy producer and resistant to White Pine Blister Rust and excellent for jelly.
Titania – It has excellent yields and large fruit and immune to White Pine Blister Rust, good resistance to Powdery Mildew.
Topsy – It has good fruit quality, very good production, and medium susceptibility to White Pine Blister rust and powdery mildew.
Older varieties of Black Currants can host a disease known as white pine blister rust that is devastating to white pine trees in North America. Plant only resistant Currant varieties including ‘Consort’, ‘Coronet’, ‘Crusader’ or ‘Titania’. In the winter season, prune out old branches close to the ground. Mature Black Currants bear best on 1 and 2-year-old branches.
Site and Soil Requirements for Black Currant Cultivation
Black Currants need rich, heavy soil. Black Currant plants prefer full sun but will tolerate light shade. Black Currants are probably the easiest of all the soft fruits to please. Any soil is suitable for Currant cultivation and they can tolerate heavier and more poorly drained sites.
Black Currant plants prefer cool moist soil. A reasonably drained, rich clay loam soil with a pH level of 6 to 7.5 is ideal. Black Currants indeed tolerate a wide range of pH and it is known that pH can be mediated by high organic levels; generally, a pH level of 6 is optimal. If the soil is sandy, incorporate peat moss, compost, or well-rotted manure to about 15 cm depth before planting. Mulching with grass clippings, bark chips or chopped straw will help conserve moisture and maintain cool soil temperature levels.
The initial setting for the Black Currant plantation is the most important factor in growing a healthy plantation. Cold air behaves like water in finding the lowest level but is slower moving. Exposed places are to be avoided as strong winds during the spring and summer season can damage the bushes and strip both flowers and fruit. Many plantations are planted adjacent to existing woodlands or hedges, but where it is necessary to provide additional shelter, windbreaks are established.
Usually, two-year-old bushes are planted but strong one-year-old stock can also be used. Plant in the spring season, just as the plants are emerging from dormancy. Set plants slightly deeper than they grew in their nursery pots and mulch after planting to keep the soil cool and moist.
How to Propagate Black Currant from Seeds
- Start Black Currant seeds in late winter approximately 2 months before the last spring frost.
- Then, soak the seeds for 24 hours in a bowl of tepid water and wrap the Black Currant seeds in moistened sphagnum moss and place the bundle inside a sealable plastic bag. Put the bag inside the refrigerator for 3 months to chill the seeds. Remoisten the sphagnum moss as needed.
- Prepare containers after the Black Currant seeds have been cold stratified. Fill about 4-inch greenhouse pots with a mixture of equal parts medium-grit sand, loam, and compost.
- Sow one Black Currant seed in each pot at a depth of about 1/4 inch. Carefully place the pots inside a cold frame or against a lightly shaded, south-facing wall.
- Maintain moderate moisture in the top inch of the soil while the seeds germinate. Let the surface dry out slightly between watering to ensure the soil doesn’t become too soggy below the surface.
- Watch for the first seedlings approximately 1 month after sowing the Black Currant seeds. Move the seedlings to a bright and sheltered area of the garden once they produce a set of mature leaves.
- Grow the Black Currant shrubs under part shade during the summer months. Then, provide about 1 to 2 inches of supplemental water each week. Transplant them into a permanent bed in autumn.
Taking Cuttings from Currants
This is a good time to take hardwood cuttings to propagate more currant bushes. Currants are quite possibly the easiest of all plants to propagate from cuttings. It’s a simple procedure and can be done while pruning to get two jobs out of the way at once.
Use secateurs to prune off a 15-30 cm long shoot of recent growth. Carefully cut horizontally just below a bud to form the base of the cutting. You can dip cuttings into hormone rooting powder if you wish, but it’s not necessary for currants. After that, insert cuttings into the soil, and then be patient. Expect to wait for 2 to 3 years for your first fruits from plants grown from cuttings, as opposed to 1 or 2 years from one-year-old purchased plants.
Spacing for Black Currant Bushes
An average Black Currant bush will need a spacing of about 5 feet and it will grow the same in height. Some varieties are slightly more or less vigorous than this and of course, it is also dependent on soil, but 5 feet is a good average. ‘Ben Sarek’ variety can be spaced 3.5 feet apart and is also shorter in growth.
How to Propagate Black Currant from Cuttings
- Black Currant cuttings propagate in late winter and wait until the shrub goes dormant and loses its leaves. Then, prepare a rooting container before gathering the cutting.
- Fill about an 8-inch greenhouse pot with medium and use standard garden loam or a mixture of compost and half coarse sand. Then, add water until the medium is thoroughly moistened.
- From the tip of a healthy Black Currant branch, gather a 1-foot-long, and 1/4-inch-diameter cutting. Take the cutting from a 1-year-old branch with plenty of leaf nodes along its length.
- Sever the cutting with sharp shears and treat the bottom one-third of the cutting with rooting hormone powder. By using a paintbrush to apply the powder in a very thin, even layer. Then, tap the stem to knock loose the excess hormone.
- Poke about 3- to 4-inch-deep planting hole in the moistened medium and then stick the hormone-coated end of the cutting into the hole. Gently firm the medium against the stem and drizzle water around the base.
- Place the potted Black Currant cutting in a lightly shaded and sheltered area outdoors. Keep the medium moderately moist but not soggy. Mist the Black Currant every other day to keep the stem hydrated.
- Check for roots in 2 to 3 weeks by lightly tugging on the stem; if it resists the tugging motion, it has rooted. It grows under lightly shaded conditions with weekly irrigation until the autumn season.
Planting Process for Black Currant Cultivation
Always buy certified stock to avoid virus problems. Approximately one Black Currant bush should yield about 4.5kg (10lb) of fruit. Usually, grow Black Currants as stooled, or multi-stemmed, bushes. Black Currants can be grown in containers in small gardens. Plant bare-root Black Currants in the late autumn season; and containerized plants can be planted at any time of year as long as the soil is not too wet. A few weeks before root Black Currant plants for autumn planting, clear the soil of all perennial weeds and enrich it with a generous amount of well-rotted manure. Add a compound balanced fertilizer at the rate of 85g per sq meter.
Carefully dig a hole at least twice the circumference of the pot in which the Black Currant was purchased if not bare-root. Add controlled-release fertilizer like Sea feed seaweed and poultry manure pellets on poor soils for individual plants if compound fertilizer wasn’t added when preparing the soil. Deep planting encourages young and vigorous shoots to develop from the base. Then, mix the soil from the hole with well-rotted organic manure and backfill the hole. Firm it in well before watering.
When planting container-grown plants, cut all the stems back to 1 or 2 buds above ground level to encourage strong shoots to develop from the base. If planting between early summer and early autumn season, wait until the plant is dormant before pruning all the stems.
Identify the positions for the holes with split pea sticks, spacing 5 feet apart from each way. A hole must be dug wide enough to accept the roots without cramping or bending them. Black Currants do better if they are planted quite deeply, perhaps a shade deeper than they were at the nursery usually, you can identify the soil mark around the base of the bush. When you are satisfied the bush is at the correct depth, infill with nicely friable soil mixed with a little compost, and then firm down well with the heel of your boot. Now, the soil should be level with that of the surrounding ground.
Bare rooted bushes will be planted during the dormant season so only a light watering to settle them in is required, thereafter no watering is required and they should have new root growth in place to support strong growth by the Spring season. For this reason, earlier planting is better than late planting, as you will find during any mild winter weather the bushes will already start to make new root growth in readiness.
Training and Pruning Black Currant Bushes
After planting you should cut all the shoots back to 2 inches from the base. Having performed this task you might stand back and having brutalized your brand new bushes. You can leave your bushes ‘up’ and they will crop sooner because of it but long term they will suffer from a lack of strong new growth in the early stages. The nursery will leave them higher than they need to be when supplying because customers don’t like to receive plants with anything to show except a few stumps and some roots.
You will find that older stems will continue to produce some fruit the bulk of the crop and the best quality Black Currant fruits are borne on second-year growth. Therefore, you should aim to remove some older stems each year pruning them back to the base in the winter. This will encourage and make room for strong new shoots to come through the next spring season, and these will then crop the summer of the next year. Aim to remove up to a third of the old stems annually and it becomes clearer as the new shoots are paler and shinier, and thick in appearance, and see the dead stalks of the previous season’s crop still adhering to the stem.
Prune Black Currants when dormant from late autumn to the late winter season. Remove weak, wispy shoots up to 4th year planting, retaining a basic structure of 6 to 10 healthy shoots. After 4th year, cut out about one-third of the older wood at the base, using a pair of loppers or a pruning saw. Prune Black Currants when dormant from late autumn to the late winter season. They fruit best on younger wood, so when pruning aims to remove older wood, and leaving the younger branches.
Fruit in Black Currants is borne mainly on 1-year-old shoots. Newly planted bushes must be pruned severely, cutting all shoots back to 2 buds above ground level. This gives the plant a chance to get correctly established before needing to put its energy into producing fruit. The remaining branches must be thinned to remove old unproductive wood and to encourage new shoots. An established bush should not be allowed to become overcrowded and have about one-third of its main branches or stems removed each year.
Manures and Fertilizers Requirement for Black Currant Cultivation
The Black Currant needs some essential nutrients to be present to enable it to thrive. The plants require nitrogen provides strong plant growth and stimulates the production of flower sprigs; phosphorus aids growth and improve crop yield; potassium promotes individual shoots development and also increases the weight of individual fruits; magnesium is a constituent of chlorophyll and helps increase yields through interaction with potassium; calcium is required for cell division is important for young plants and buds.
Fertilize in late fall by spreading a 1-inch layer of composted manure over the root zones of the plants. It is important to slow-growing plants can be fed again in the early summer season. Spent mushroom compost can be used but care should be taken as it contains lime and Black Currants prefer slightly acidic soils. The Black Currant benefits from additional nitrogen, and phosphatic and potash fertilizers must be applied annually. A balanced artificial fertilizer can be used and a 10-10-10 granular product can be spread around the bushes at the rate of about 100 to 240 grams per plant. Weed development can be suppressed with organic mulch such as sawdust, bark, mushroom compost or straw, heavy plastic topped with an organic mulch cover, or landscape fabric.
Black Currant Plant Care
- Water Black Currant plants during dry periods in the growing season. Re-pot container-grown Black Currants every 2 or 3 years.
- Black Currants tolerate a wide range of soil conditions but prefer well-drained and moisture-retentive sites.
- Black Currants like to be fed. Sprinkle with general fertilizer each spring and top dress with well broken down animal manure or compost.
- Pruning is best done when the plant is dormant, but start pruning after the plant has finished fruiting in the late summer or early autumn season. The principle of plant pruning is to encourage new shoots to arise from the ground. Also remove broken, weak, diseased, or misdirected branches. Do not shorten new wood.
- Usually, birds will be the main problem during fruiting time so you can place a net over your canes to prevent birds from eating your fruits.
Pests and Diseases Management for Black Currant Cultivation
Big bud mite – These mites infest the buds of Black Currant bushes and ‘Ben Hope’ currant is a resistant cultivar.
Black Currant gall midge – Tiny and white maggots feed on the shoot tips of Black Currants, preventing leaves from reaching their full size; affected plant leaves dry up and die. Shoot tips can also die back. Plant cultivars such as ‘Ben Connan’ and ‘Ben Sarek’ are resistant to Black Currant gall midge.
Capsid bugs – These green insects suck the sap and then cause small holes to appear on the plant leaves, which develop reddish-brown spots. Then, spray with pyrethrum as soon as the symptoms are noticed.
Reversion – This virus is transmitted by big bud mite. It causes the leaves to turn yellow color, and flowering and yields are dramatically reduced. There is no cure for this problem and then plants must be removed immediately. And, always buy certified virus-free plants.
Greenfly and Aphid – These are the most commonly troublesome critters, causing soft new growth to curl and become distorted, sometimes it becomes streaked with yellow. Then, these insects overwinter on the bush so the first step to eradication is to provide a winter wash all over the bush whilst it is dormant. Insecticides are still effective but you need to start early, soon after the first leaves emerge. Black Currants already show a sign of heavy infestation, is prepared to snip off the ends of the new growth where the damage is worst, and then spray.
Mildew – This is a commonplace problem with Black Currants and is more troublesome with the older varieties but not exclusively so. It is easily dealt with by a proprietary insecticide but again prevention is better than cure so start an early spraying program to prevent it from getting a hold in the first place.
Leaf spot – Leaf spot begins life as small brown color spots on the leaves which gradually become larger and coalesce. Usually, leaves fall prematurely and the resultant crop is affected. The disease can be mainly controlled by the use of a broad-spectrum fungicide, applied shortly after flowering. Extra feeding is effective to help the bushes regain the vigor that has been lost.
Big bud mite – These mites infest the buds of Black Currant bushes. ‘Ben Hope’ is a resistant cultivar. Dispose of heavily infested Black Currant plants has been picked and then replant in autumn with clean new stock. One mite-resistant cultivar, ‘Ben Hope’, is available.
When and How to Harvest the Black Currant
Usually, harvest Black Currant fruit when they are dark and ripe. Black Currants freeze very well. Normally Black Currant berries ripen over 2 weeks and once ripe will stay on the bush for a week without becoming overripe or falling off the bush. The end-use for the berry, whether it will be used in processing, the fresh market, quick-frozen, or made into jams or jellies will determine whether the berries can be harvested in one or two pickings. With more frequent picking, there is a tendency to pick fruits that are not fully ripened.
Whether Black Currants are harvested by hand or by mechanical harvesters the berries must be taken out of direct sunlight and then stored in a cool area until they are processed or brought to the fresh market.
Commonly Asked Questions about Black Currant Cultivation
Black Currant Plant
How long do Black Currants take to grow?
Black Currant takes at least 2 years to produce a good standard Black Currant so the price is much more expensive than a normal bush.
Do Black Currant bushes spread?
To restrict the Black Currant bushes to a height and spread of about 120–150 cm. The ideal time for getting them in the ground is the late autumn to the early winter season.
How long do currant bushes live?
Currant bushes live approximately 12 to 15 years.
What do you feed Black Currant bushes?
Black Currant bushes require plenty of watering and feeding. In spring, feed with pelleted chicken manure or other high potash fertilizer, and add thick mulch.