Perennials which have been in place for a long time and are well developed can be propagated by the method of division, which is typically done in the autumn, when the plants are about to enter a period of dormancy. Start by removing the plant from the soil in which it is grown; shake it well to remove the soil attached to the roots, so that we can better assess the size of the root system. To get new plants divide the clump in several portions, trying to avoid damage to the vegetative parts. For this operation use shears that are sterilized and properly sharpened, to make clean cuts, and you should also clean and disinfect the shear blades again each time you want to divide up a new plant. Check that each new piece retains a good amount of well-developed roots, to promote grafting in the new plant. Once the new plants are prepared, plant them in plenty of soft, rich soil, which must also have excellent drainage. Then water the soil thoroughly.