No other form of reproduction is as simple as division. Through division one gets several vital individual plants that can be re-arranged. Also, rejuvenated plants are healthier and grow more happily.
Make two out of one
Did your shrubs become too large or lazy of blooming or show up dried parts inside, then you should allow them a makeover. For all spring and early summer flowering bulbs now is the best time to do it. Dig the perennials out deep and divide them by hand into fist-sized pieces using a spade or knife. Remove dry and dead plant material as well as weeds. Each new plant is cut with scissors to approximately one-third from the top and one-third at the root, so everything is growing well again. Water well after planting.