Planting a Garden

How to Divide Perennials

Separating plants into divisions results in growing smaller plants faster.
Separating plants into divisions results in growing smaller plants faster.

Easily divide daylilies, hostas, astilbes, or other clump-forming perennials with a sharp shovel. Just slice off an edge of the clump in spring or late summer. Uproot it and replant elsewhere. Keep the new division watered for at least several weeks or until it has regenerated lost roots.

Divide a large perennial clump into small divisions to get many little plants fast. This is a quick and easy way to make enough plants for the big drifts of perennials such as asters, goldenrod, sneezeweed, and blazing stars before encouraging them to grow. Division renews a declining clump of perennials. As many perennials grow, new shoots emerge at the perimeter of the clump, which keeps spreading outward. The center becomes increasingly older -- sometimes woody, sometimes completely barren. In spring, late summer, or fall, dig up the entire clump. Cut out the old heart and discard it. Refresh the soil with organic matter, and replant the healthy young pieces.

Perennials that can be divided easily include asters, daylilies, yarrow, phlox, lady's mantle, salvia, coreopsis, hardy geraniums, irises, mint, thyme, oregano, and winter savory.

Here's how to make smaller divisions:

  • In spring or late summer, dig up the entire perennial plant clump and wash soil off the roots with a hose.
  • If dividing in late summer, cut back the foliage by half or more.
  • Use your hands to break rooted sprouts into individual pieces. If roots are too hard to work apart by hand, slice them free with a knife or pruning shears. Each section should contain at least one leafy sprout and one healthy root.
  • Replant very small divisions into pots of peat-based planting mix and tend them carefully until they get a little bigger. Larger divisions can go right back into the garden if kept moist until they become reestablished.

Keep reading to learn about plants from seeds indoors.

Looking for more information about gardening? Try these:

  • Gardening: Learn the basics of successful gardening.
  • How to Start a Garden: Even beginning gardeners can get a healthy garden in the ground and growing.
  • Annuals: Plant these beauties in your garden for bountiful blooms all summer.
  • Perennials: Perennial plants grace your garden year after year.