Dividing your perennials has many benefits. It helps rejuvenate the plant and stimulate new growth, control the size of the plant, and increase the number of plants. A general rule to follow is to divide spring and summer blooming perennials in the fall and fall blooming perennials in the spring. Dividing when the plant is not flowering allows all of its energy to focus on regenerating root and leaf tissue. To divide perennials, dig up the parent plant using a spade or fork. Gently lift the plant out of the ground and remove any loose dirt around the roots. Separate the plant into smaller divisions by teasing the roots apart or cutting them with a sharp knife or spade. Plants may also be separated by placing two forks in the center of the clump back to back and pulling them apart. Each division should have 3 to 5 vigorous shoots and a healthy supply of roots. Keep these divisions shaded and moist until they are replanted.