An ideal time to divide perennials is just as they are emerging from the ground. There will be a minimum amount of disturbance. They should be divided before flower buds are visible if possible. If you want to move plants to another area, dig the entire plant and then divide it into 2 or more pieces before replanting. You can also dig half a plant and leave the other half in place. Excess plants can be placed in pots to share with friends or neighbors. Perennial flowers which bloom early in the spring can be divided when they complete blooming.