Blackcurrants fruit on younger wood which is why they need all the old growth taken out, you can tell the old growth because it darkens as it ages. If the wood is black, take it out, make sure it's cut above a bud that faces outwards etc. They usually are productive for about 10 years. Cuttings taken from the younger wood are more likely to be successful as the wood is still growing.
We took 9 cuttings from young growth on 1 plant and 8 of them took. An older plant, a third of the cuttings took.
Your in France, have you ever grown pinkcurrants? Their a French variant that's only just becoming available in the UK, we've 3 plants on order.
