A sheltered spot with a reasonably fertile, moistureretentive and well-drained soil is preferable for blackcurrants. If it has a slightly acidic pH (around 6–6.5 – testing kits are cheap and widely available) that’s all the better, but it’s not essential. Avoid placing them in frost pockets, as a late frost can damage the flowers and lead to a smaller harvest.
Although blackcurrants will tolerate partial shade, the fruits taste better when exposed to plenty of sunshine, and shaded bushes may become weak and leggy. A few weeks before planting, always clear the ground of weeds, especially perennial types such as dandelions or docks, and enrich the soil with plenty of well-rotted manure or compost.
Most blackcurrant bushes are sold as bare-rooted plants and the ideal time for getting them in the ground is late autumn to early winter. Any time up to mid-March is also fine (as long as the ground isn’t waterlogged or frozen) but they will have less time to settle before starting into growth. Container-grown specimens can also be purchased from garden centres or nurseries and planted throughout the year – but whenever possible, opt for the autumn, early winter or spring. Whatever the month, planting should always be avoided if the ground is very dry, frozen or waterlogged due to heavy and persistent rain or poor weather conditions. For the best results, select bushes that are certified as virus and disease-free and have at least three obvious stems.
Space the bushes 1.5m apart in the ground, and set them about 5cm deeper than they were planted in the nursery – an obvious soil mark is usually visible on each plant. This will encourage the stem bases to form roots as well, and eventually give the bushes more support.
Once the new bushes have been planted in the ground, it’s absolutely essential to water and firm them in well. A 7.5cm-deep mulch of garden compost or well-rotted manure should be spread around each plant – this will help to feed the blackcurrants and keep down unwanted weed growth. At this stage, the main stems also need to be pruned to two buds from ground level (these buds should face outwards rather than inwards as that’s where you’ll want your fruit to appear). The reason for this is to channel the plants’ energies into establishing the root system in the soil and encouraging the production of lots of healthy new stems (from above and below ground) in the spring and summer. It’s these that will produce the first crop of fruits the following season.
New and established blackcurrant bushes must be kept wellwatered during long spells of dry spring and summer weather, and weed control is vital all year round. However, the plants have a wide-spreading, shallow root system and so using a spade, fork or hoe around them could mean you can damage it accidentally; a combination of hand weeding and mulching is less likely to cause damage.
For bumper crops, feed the bushes with an organic fertiliser (applied at a rate of approximately 100g per square yard) in the early spring and top-up the mulch of compost and manure around each plant every April. The plants can also be given a boost by applying an organic liquid fertiliser when the fruits are starting to swell in the summer.
In harsh winters, the roots (or rootballs) of new bushes can sometimes be lifted out of the ground by hard frosts. If this happens, firm them back in immediately. The flowers of some varieties (notably older types) are prone to cold damage and, if a frost is forecast while they are blooming, it is a good idea to carefully drape horticultural fleece over the bushes.
Unfortunately, currants are sometimes sought out by hungry birds and the developing and mature fruits may need protecting by covering with a sheet of fine netting. Alternatively, dangle old CDs from string nearby or hang thin strips of recycled tin foil from the stems – these will glint in the sunlight and rustle in the slightest breeze to frighten away any passing birds.
Blackcurrant fruits are ready for picking in the mid to late summer (July and August) and are at their best about seven days after they have turned blue-black. They can be gathered individually or, if you want them to stay fresh for a little longer, you can harvest them as whole trusses. If possible, pick the blackcurrants in dry conditions, as wet fruits often don’t store well and may turn mouldy. The fruits can be eaten immediately, or stored in a fridge for one to two weeks. Alternatively, they can be frozen for eating later – they should last at least six months this way.