Start new plants
Divide clumping perennials
Early spring is the ideal time to put propagation techniques to work, such as grafting flowering shrubs and fruit trees and sowing annual flower seeds, vegetable seeds, and some perennial seeds indoors. But out in the garden, the primary propagation practice of early spring is dividing perennials.
Division is a method of propagation by which a clumping perennial is separated into smaller clumps or individual plants, each with roots and buds. The smaller clumps or plants, called divisions, are then replanted.
To divide many herbaceous perennials, such as Shasta daisies, daylilies, and hostas, wait until a clump breaks dormancy and the new leaves are an inch or two long. Use a garden fork or spade to loosen the soil around the outside edge of the clump. Slip the tines deep into the soil and rock the tool forward and back, going around the entire perimeter of the clump twice. Repeat this procedure once more using the fork to lever the plant free from the soil.
To divide a large clump, place the tines of two garden forks back-to-back in the center of the clump. Drive the forks into the clump and push the handles apart to separate the plant into two clumps. Smaller clumps can be divided by gently separating individual plants with your fingers or a gardening knife.
Very large clumps can be heavy and are often best divided while still in the ground. Use a garden fork or spade to loosen and lift manageable divisions from the outside edge of the main clump.
Once the divisions are separated from the main clump, it is best to replant them as soon as possible. Immediate replanting is the best way to ensure healthy, robust growth and hasten the plant’s establishment in the garden.
To replant a division, dig a hole about as wide as the spread of the plant’s roots. Make the hole half as deep as it is wide. Fill the center of the hole with a mound of soil and set the plant atop the mound so the base of its crown is level with the surrounding soil. Fill the hole by adding soil from the edges, working your way toward the crown of the plant. Settle the soil by watering gently but thoroughly.