All kinds of roses require a periodic and appropriate pruning. This is the most important procedure for the future life of the plant as well as for the flowering. A weel-done pruning can change the shape of the plant, stimulating the leafage and dramatically affecting the reflorescence, both with regards to distribution of the flowers on the plant and to the dimension of every single flower.
Different varieties need different pruning, but the best period is 2-3 weeks before the regrowing of the vegetation, that is from January 15/20 to March 15/20, depending on the latitude, the exposition to sun and the altitude. Anyway, plants cannot be pruned during winter months, since ice could hit the new branches compromising their growth.
During spring and summer, you have to remove withered flowers, cutting the stalk 3-4 flowers under the flowers themselves. In the case of hybrids of musk it is possible not to prune them after they last flower in autumn, in order to leave the ornamental berries on the plant.