If your garden looks like mine, you probably have lots of overgrown perennials. The abundance of rain during the past couple of months has encouraged lots of plant growth. Take a walk around your garden and make note of plants that are ready to be divided.
Perennials are ready to divide when the side shoots or runners become crowded by other plants. Some perennials are aggressive and may need to be divided every two to three years. Examples include: Achillea (Yarrow); Aster; Centaurea montana, (Mountain bluet); Centranthus ruber, (Red valerian); Coreopsis; Dianthus; Geum; Lychnis coronaria, (Rose campion); and Veronica.
|Some species of Veronica will benefit from dividing every two to three years.|
|Daylilies are easy to divide and transplant|
|Penstemon cardinalis reseeds readily, providing "volunteers" for transplanting|
To divide perennials, use a spade, shovel or fork to dig around and under the entire plant and lift it out of the soil. This is easier if the soil is not saturated. Remove most of the soil from the roots by hand or by washing with a hose. Use pruning shears or a sharp knife to cut apart the healthiest part of the plant, often on the outside. Most clumps can be divided into four or five smaller clumps, after dead and discolored parts are removed. Replant divisions as soon as possible and protect with mulch. Don’t forget to water the new transplants and keep them moist until they are re-established.
Check out CSU Extension’s Fact Sheet#7.402 for more information on growing perennials.