Our currant bushes gave their first proper crop last season. They bore very well indeed, and the fruit quality was excellent, especially the red currants, which were large and sweet, and held on nice long strigs. The buds will soon break, so it was the last opportunity to look at pruning them a little before the coming season.
Black currants, red currants, and white currants have the same superficial appearance, but the fruiting habits of the black currant are quite different, hence, the pruning regime is also different. Black currants fruit best on the young wood produced the previous season and to a lesser degree on the slightly older wood. Old wood becomes unproductive, so to maintain a productive bush, pruning focuses on removing around one third of the oldest wood, to encourage and allow space for new growth to develop.
The usual rules of pruning apply. First, remove any diseased stems, cutting well back into good healthy wood. Second, address any crossing branches, pruning back one or other, or perhaps both, depending on which is best placed and, in the case of black currants, which is the youngest wood. Third, prune to develop an open shape, which will promote good air flow and minimise problems with disease.
One of the black currants appears to have quite a narrow, vertical, habit, so we pruned out a fair bit from the centre to open it up again. There was no disease or damaged material with these, so nothing else to worry about.
Red and white currants have a habit much like gooseberries, fruiting on old wood, so that a more or less permanent framework can be established. Pruning is more about keeping things tidy. They have only been in place a couple of years, so I did not have much to do with them this winter. We pruned back some crossing side shoots, and pruned away a little poorly placed growth. We also tipped back quite a few of the branches, which showed signs of pest damage. Aphids, in sufficient quantity, congregating at the tips of the stems, cause the leaves to curl and the stem to grow distorted. We simply cut back to a well placed healthy bud lower down the stem to remove this damage.
Although the red currants will continue to be productive on the existing framework, one of the bushes had thrown up some new growth from the base. Normally, red currants are grown on a short leg, whereas black currants are planted deep so as to develop a stool. Thus, one might not expect the sort of growth that we found. However, these currant bushes were supplied without the desired leg and when planted to the previous soil mark they are positioned much as for the black currants. One of the new stems was poorly placed so was cut out. The other two look quite useful for replacing the older wood. Whilst we can retain the old growth, where the bush produces vigorous replacement shoots, it may well be a good idea to use these to rejuvenate it. This is not particularly important right now, but may become more so in future years. In any event, we tied in one of the shoots to an existing branch, which it will replace after fruiting, and the other we tied to a short cane to train it in the direction we wanted it to grow.
A little attention to pruning now should keep these bushes in good condition for the coming season, and even though I have removed a fair bit of growth from the black currants, there is plenty left to bear a crop, and the renewal of this wood should keep them productive for years to come.