Blackberries / Hybridberries / Japanese Wineberries
Blackberries will tolerate most locations including areas of partial shade and soils that do not have good drainage. As for raspberries, ensure you are planting these in fresh ground wherever possible, if not, it is recommended to remove and replace the existing soil to a minimum of spade depth. It should be noted however, that this is not always effective at preventing the virus from spreading. Prepare a 2ft x 2ft ( 60cm x 60cm) area at each planting spot by digging a hole approx. twice the diameter of the root-ball or pot. Line the bottom of the hole with fresh compost or well rotted manure. If using manure, also ensure it is well mixed in with the soil.
Blackberries will need to be trained against either a wall, shed, fence of on a post & wire system (see raspberries for set up instructions). Plant with the old soil mark (if visible) level with the surface – this should be no deeper than 4 inches. Plant at a distance of 8ft (2.3m) apart training left and right from the centre. Line the bottom of the trench with fresh compost or well rotted manure. If using manure, also ensure it is well mixed in with the soil. Take each plant and spread out the roots evenly, the old soil mark (if visible) should be level with the surface. Replace the soil by gently treading it back in and it is a good idea to apply a general purpose fertiliser mixed in with the soil at this time, ensuring the cane get the best possible start. Water in well.
Once picking is over, cut back the recently fruited cane to near ground level. Once the plant is established, the simplest method of training black/hybrid berries is by tying the new cane in the opposite side of the centre from the established fruiting cane, this enables easy pruning of the fruited cane down to near ground level, and allows the new cane to grow freely.
Water in a general purpose fertiliser i.e. Growmore, in March. Once this is done, apply a mulch such as well-rotted manure or compost. This will help keep the soil cool & moist as well as keep down the weeds. Regular weeding is important. Hand weeding is recommended, however if using a hoe, ensure you don’t go too deep to avoid damaging the roots which can lead to suckers being produced. Watering is vital during spells of dry weather.
To grow as a primocane (ie producing two, smaller crops each year), cut back the new spring stems, which have produced fruit at their tips in autumn, to a point just below where the blackberries were produced, soon after they have finished cropping. These half-canes can then be left to overwinter, will put on new top growth in spring and will then go on to produce the first crop of berries in early summer. After these two year old canes have finished fruiting they should be cut right back to their base. In the meantime, new canes will have emerged from the base of the plant in spring and these should be tied onto their support as they grow. These new canes will then produce the second, later crop and should have their tops lopped off after fruiting. This then creates a repeating cycle.