Currants are fruit that come from the botanical family Grossulariaceae and the genus Ribes. There are three main types of currant: black, red, and white/pink. White and pink currants are albino selections from red currant bushes and are less acidic. They are shrubs that lose their leaves each year, and they come from areas with lots of trees in northern parts of the world.
Different cultivars of Ribes have similar growth habits and appearance, with only slight variations. The gooseberry bush and the currant bush are closely related. They have a similar growth habit. They are medium-sized shrubs that grow to be about 3-5 feet tall and spread out about the same distance. They have an upright growth habit, which means they grow straight up more than they spread out. Buds appear in late spring on this plant, followed by mid-green leaves. The leaves have a palmate appearance, with 5 lobes and serrated margins. Stems are brown and woody when old. After a year, new growth turns from green and flexible to light brown and woody.
Small green and brown or green and white flowers grow in clusters among maple-like leaves in late spring. The clusters open to reveal long cream or red and brown flowers, depending on the variety. The leaves of black currants are rounder than those of white, pink, or red currants. Most currant varieties can pollinate themselves, so the flowers don’t stay open for very long. The flowers then swell and turn into small, round, green berries. You only need one plant to produce berries. Black currants turn from light red to purple/black as the spring season comes to an end. The berries produced are around half an inch in diameter.
Currant shrubs lose their leaves in late fall and remain inactive until the following spring. This is the best time to prune and propagate. Pruning helps keep plants healthy and productive. More on this later. Some popular and widely grown varieties to look out for are:
- Black currant – ‘Titania’ – Heavy producer of good quality large berries. Resistant to blister rust and powdery mildew.
- Pink currants – ‘Pink Champagne’ – Excellent flavor and good highly resistant to disease.
- White currants – ‘White Imperial’ – Good, sweet flavor and resistant to powdery mildew.
- Red currants – ‘Honeyqueen’ – Harvests of this red currant occur over a long period and have great flavor. Another stunning cultivar is the Red Lake variety.
Planting Currant Bushes
Bare root currants should be planted in autumn. Planting your tree will be easier if you soak the root ball in water for a few hours before you start. Shrubs can be planted at any time, but are best in autumn.
Select a site that is well drained and has moist, rich soil. Select a location for your plant that gets full sun to partial shade, has well-drained soil, and is moist. Currants that are grown in warmer climates will do better when they are in shade during hot weather. Soil should be rich, well-drained, and moisture retentive. Improve the planting hole for the plants by adding a lot of organic matter so they will have a good beginning. While they typically grow best in the ground, deep and heavy containers can also work well so long as they won’t blow over as the plant gets bigger. If you are growing plants in containers, make sure that you water and fertilize them on a regular basis.
Currants can be planted a little deeper than they are in the nursery pot. The shallow roots of the tree need to be anchored into the ground in order to support the weight of the fruit. dug a hole that was twice as wide as the root ball, and then filled it with fresh organic matter. Position the root ball, then fill in around it with soil. Firm it in, then top with mulch to help fellow moisture and prevent weeds. Keep the soil moist until they are established. If you are growing your plant in an exposed site, you may want to provide a cane for extra support. They should be spaced 4-5 feet apart.
Caring For Currant Plants
Sun and Temperature
A plant that is grown in full sun will produce more fruit than one that is grown in part shade. Currants grow best in cooler conditions and prefer some afternoon shade in warmer climates. If the temperature is above 85 degrees Fahrenheit and there is intense sunlight, the leaves may fall off. A layer of mulch around the base of the plant helps it to hold onto moisture and stay cooler. Currants are very tough and don’t need any frost protection unless there is a chance of a late frost while your plants have flower buds. Floating row covers can protect your plants from frost until the risk has passed.
Water and Humidity
Water the plants regularly from early spring until you harvest them, keeping the soil moist but not wet It is best to water plants in the morning so that they will be rehydrated for the day ahead. This can be done using a soaker hose or watering cans. You should water your plants at the roots instead of the leaves to make sure the moisture actually gets to them. Watering your plants consistently during the summer can help prevent the development of powdery mildew. After you harvest your crops, you can reduce your watering and it isn’t necessary to water them over the winter into late winter.
Soil
This berry plant prefers soil that is able to retain moisture and has good drainage, with lots of organic matter like composted manure added to it. The best soil type for this plant is loamy, slightly acidic soil with a pH preference of 5.5 to neutral.
Fertilizing
Adding a thick layer of compost or leaf mold in spring will improve the soil quality by adding nutrients and retaining moisture. Apply a balanced fertilizer to your berry bushes every few weeks during spring to increase fruit production. Too much nitrogen can slow down fruit and flower production, and encourage a lot of new shoots of leafy growth and disease.
Pruning & Training
Pruning the plant properly is key to keeping it healthy and producing a lot of fruit. Fruit is most abundant on wood that is two or three years old, although it can be found on one-year-old wood as well. The goal is to cultivate stalks that are sturdy enough to uphold the heft of the fruit. Plants should be pruned when they are dormant in winter or early spring.
Cut newly planted berry bushes back to an inch or two above soil level and just above a leaf node. It may seem drastic to delay fruit production by a year, but it will help your plant to develop a strong root system and an open structure. The newly planted older stock should be cut back by half to avoid wind rock and root damage over the winter months. This will help the plant to remain healthy and avoid any potential damage that could occur during the colder months.
Cutting back a young tree by a third or less in its first three years will help it maintain its shape and get rid of any damage. This is a great way to encourage fruit production. Older bushes should have a quarter to a third of the plant removed, including any damaged, diseased, diagonal, or dead branches. Remove any stems from the plant that are 4 years or older, as well as any stems that are not producing, back to the base. Prune above an outward-facing leaf node or bud to keep the open, airy structure.
Propagation
To propagate currant shrubs, you can use seeds or hardwood cuttings, just like other fruit trees.
After you have harvested your summer berries, remove the seeds from the pulp and leave them to dry. Seeds require a period of cold stratification to germinate successfully so in early fall wrap seeds in some moist compost or sphagnum moss placed into a tub with holes to allow air circulation and place the tub in the fridge or outside away from direct sunlight for around three months. Plant the stratified seed individually into 3in (9cm) pots filled with fresh compost around 6-8 weeks before the last frost. Keep the compost moist by spraying it with water occasionally, and set it in a cold frame or cold greenhouse until after the last frost date.
In late fall, cut 10-12 inch long hardwood cuttings from 1-year-old wood. Dip the cut end of the stem in rooting hormone and insert it into a tall pot filled with compost until only an inch or two of the stem is visible. Put potted plants in a shady spot where they will be protected from the sun’s rays. You can also plant the cuttings directly into trenches outside. Mix in lots of organic matter to the trench and compact it around the cutting. Trees will not be ready to plant in their final location until leaves have sprouted and strong roots have developed. This can take around 6 months.
Harvesting and Storing
Harvesting Currant Plants
Most currants will be ready to harvest from the early summer months and onward. This text is saying that black and red currants will be large and full of juice when they are ripe and ready to be picked. The color of the ripe fruit will be either a deep red or a blackish purple. The best way to tell if your white and pink currants are ripe is to taste and/or squeeze them. The berries are ready to eat if they are soft, have adequate juice, and taste sweet.
Cut the bunches of berries off the stem, rather than pulling them off. Pulling can damage the berries and break stems. Pruning during harvest can remove broken or diseased branches. It’s best to wash berries and eat them right away for the freshest taste.
Storing
The best way to eat these is soon after harvest, but they can be stored in the fridge for a few days. Berries can be frozen in bags for up to 6 months. Berries can also be dehydrated to make dried currants. You can keep dried currants in the fridge for up to a year, as long as you store them in an airtight container. Black currants can be turned into different kinds of preserved foods like jelly or syrup.
Pests And Diseases
If you see resistance information about a particular disease for one variety of fruit but not another of the same kind, then that variety may be susceptible or might not have been tested, so its resistance is unknown. The following are some of the more common issues.
Anthracnose Leaf Spot
Symptoms
Leaves get brown spots, turn yellow, then fall off.
Control Methods
Copper fungicide applied in fall, winter, or spring. Prune out weak or injured wood.
Comments
Rake leaves from under plants in the fall.
White Pine Blister Rust
Symptoms
Extensive reddish-colored blisters on black current leaves. Defoliation often occurs in bad infections.
Control Methods
Spray copper fungicide in the fall before rains. Repeat in early spring.
Comments
Back and flowering currants are more likely to be affected than red and white currants. Do not plant within 900 feet of white pines or pines with five needles.
Imported Currant Worm
Symptoms
The leaves have been eaten, starting at the bottom of the bush and moving up and out. Small green caterpillars line chewed leaf edge. Can appear to be defoliated almost overnight.
Control Methods
Use pyrethrin or rotenone on the first generation of caterpillars you see, and subsequent generations, throughout the summer. Search daily and destroy by hand. Cover with floating row cover.
Comments
Ducks find new caterpillars easily. Use Bioneem or Spinosad.
Currant Fruit Fly
Symptoms
If a fruit is infested with maggots, it will ripen and fall early.
Control Methods
Spray with rotenone at petal fall. Or use spinosad or bioneem. Pick up and discard affected fruit. Use a floating row cover to protect the bush during fruiting, but make sure it is tied so that pests cannot come up from below. One way to reduce the population of pests is to shallowly cultivate the area around bushes, which exposes the egg cases and larvae to predators.
Comments
If you put plastic down around your fruit when it is ripening, it will help keep larvae from getting into the ground.
Spotted Wing Drosophila
Symptoms
Eggs are deposited 7-10 days prior to fruit ripening; holes in fruit, spotty molding, larvae in fruit, exuding berry sap, scarring.
Control Methods
Monitor with traps. Spinosyn-based insecticides. In the fall, adults of this species feed on over-ripe or split fruit (both vegetable and tree fruit) to prepare for winter.
Comments
For up-to-date information on Spotted Wing Drosophila, go to https://agsci.oregonstate.edu/spotted-wing-drosophila/what-backyard-fruit-growers-need-know-about-swd-drosophila-suzukii-fly-pest. You can also get information from your local co-operative extension office.
Deer
Symptoms
Browsed shortened branches. The leaves of plants are eaten, or the plants are pulled up.
Control Methods
Fences or cages at least 8’ tall. Plastic mesh, electric, or woven wire fences.
Comments
An 8′ woven wire deer fence has been the most effective at Raintree. Repellents are not always effective, and the only way to guarantee protection is to have large dogs patrol the perimeter. Some have had success with the product “Deerchaser.”
Bird
Symptoms
Fruits disappear or have gaping holes in them. Most fruits are susceptible to damage from cold weather, with strawberries, blueberries, cherries, and filberts being the most vulnerable.
Control Methods
Reflective Bird Scare Tape can work well. Bird netting. Cages.
Comments
The blue jays start harvesting filberts when they are ready to be picked, and you should do the same. Nuts dropped by jays are usually empty.
Vole/Mouse/Rabbit
Symptoms
The bark is eaten in a strip from the ground up to 8 inches, and the roots are eaten as well. This usually happens in snowy areas with a lot of mulch or tall grass around the base of the tree.
Control Methods
Keep mulch 4”-6” away from the trunk. Keep grass short and 1’-2’ from the trunk. Wrap a vinyl tree guard around the trunk of the tree until it is well-established.
Comments
Voles and mice will chew a couple of inches above the ground and also into the root system, causing the grass to die. Rabbits are known to chew on apple trees, and can cause damage up to 8” high.
Aphid
Symptoms
This text is discussing pear-shaped insects that are 1/32 to 1/8” long. These insects multiply quickly, and can often be found on the underside of leaves and stems. Can be pink, green, black, or white. Leaves with red blisters or that are curled down, and stems that turn black with sooty mold are indicative of this disease.
Control Methods
Ladybugs and parasitic wasps typically prey on other insects and help to keep their numbers in check. Knock aphids off with water spray. To control for aphids on, spray with Pyrethrin, Rotenone, Insecticidal Soap ,or delayed dormant oil. Control ants if they are also present.
Comments
Trees can tolerate some infestation. Monitor in late spring and summer. Control is more important on new trees. Grow plants that attract predators, i.e. dill or yarrow.
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