How to Prune Blackcurrants in Two Easy Steps
Pruning black currants is not complicated. You just need to understand a few basic principles:
You've probably already encountered the question of how to prune black currants properly to keep the bushes healthy and productive each season. Pruning blackcurrants affects how much energy the plant puts into growth and how much energy it puts into yield. Of course, it also affects the strength and health of the currant bush.
You can find several methods of currant pruning in the literature, but all types of pruning and cultivation forms are based on the same rules. Once you understand these basic principles, your annual black currant pruning will be a simple routine.
When to prune black currants
The ideal time to prune black currant bushes is at the end of winter, when the plants are still dormant but the threat of severe frosts (below -10 °C (15°F)) has passed. This means the right time for pruning black currants falls between January and March, depending on the climate zone and temperature conditions of current season. Trimming black currants too early means that heavy frosts could damage the newly-cut ends of the branches and, conversely, if trimming to late means that plant sap could ooze out of the cuts, putting extra strain on the plant. In any case, avoid pruning any parts of the plants that are already sprouting, as this weakens the plant.
The essence of black currant pruning
The black currant bears most of its fruit on two-year-old wood, with some additional fruit on one-year-old wood. Branches older than two years produce a gradually smaller and lower quality yield, so proper pruning to encourage new growth will keep production high. The essence of blackcurrant pruning is therefore the annual removal of old wood and the reduction of the fruiting branches so that the plant produces a good quality crop and remains healthy.
Step 1: Clean up
If we let a black currant grow without pruning, it will put too much of its energy into growing old wood, which means that the fruit-bearing two-year-old wood ends up comprising only a very small part of the plant. The first step in effective pruning, therefore, is to remove the three-year-old and older wood that produced fruit in previous seasons. To do this, cut off old and damaged branches completely, as close to the ground as possible. Three-year-old and older wood can be recognized by its thickness and darker color.
Overall, your goal is to let each branch grow for two years, and then remove it just above the base of the plant to make room for younger shoots to grow. In this way you will have a continuous mix of one and two year old branches on the plant, ensuring a harvest in the current season as well as a harvest for next year.
Step 2: Thin out
The goal of this step is to leave only promising one- and two-year-old branches on the plant, opening up space for air circulation inside the shrub. The ideal number of branches left on the black currant bush depends on the strength of the plant: an older, more vigorous currant with a well-developed root system can handle a larger quantity of fruit-bearing wood. This usually means leaving 6 to 12 branches growing from the base of the plant on one shrub, of which 3 to 6 branches should be two-year-old.
Always leave the healthier and more vigorous branches on the shrub, leaving the central part of the plant open for light and air circulation. As you’re assessing your plant, look for branches that are drooping or growing horizontally and target them for removal. You can also remove crossing branches or branches pointing towards the center of the shrub. Do not cut back the tops of branches (unless it is for aesthetic reasons).
The result should be a shrub with branches that are well spaced apart to ensure good air circulation and greater disease resistance. Overall, expect to remove a total of 40 to 60% of the plant by pruning each year.
Black currant pruning tips:
• Sharp pruning shears ensure clean, smooth cuts, so sharpen them before black currant trimming each year.
• If you prune black currant plants too much, you will deprive yourself of a good crop, because the bush will invest its energy in the production of young shoots. If, on the other hand, pruning is insufficient, you may get a higher yield, but the fruit will be smaller and the plant will gradually weaken, leading to a lower yield in following seasons. It is therefore important to maintain a balance between the yield and the growth of the black currant shrub.
• Currants need plenty of space to grow. Think about this when planting your currant shrubs and give them a place in the garden with plenty of light and air circulation.
• For currants grafted on rootstocks, the pruning procedure is identical, except that the old branches are removed by pruning them off above the spot from which they grow out of the trunk.
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