Deb Babcock: Dividing perennials in the fall |

Deb Babcock: Dividing perennials in the fall

Deb Babcock

Now is a good time to propagate many of the perennials in your garden if they’ve become overgrown, if you just want to have more of a particular plant or if they seem to have lost some of their heartiness.

It’s pretty easy to do and is an inexpensive way to add plants to your garden (or for swapping plants with friends and neighbors).

Although some plants are best divided in the spring, many of the plants that grow well in the Yampa Valley can be split right now and replanted before the snow flies.

Among those plants that can be divided now are Achillea (yarrow), Anemone, Astilbe, Campanula, Coreopsis, Galium, Helianthus, Hosta, Iris (early fall), Kniphofia (red hot poker), Lamium, Liatris, Lilium, Lycoris (crocus), Monarda (bee balm), Nepeta (catmint), Paeonia (peony), Papaver (poppy), Polemonium (jacob’s ladder), Potentilla, Pulmonaria (lungwort), Sedum, Veronica, and Viola (violets).

To divide a perennial, start gently digging as far out as the drip line of your plant, trying to disturb the roots as little as possible. If the roots are extending out a long way, use your trowel or shovel to make a clean cut through the roots all the way around the plant and then lever it out of its planting hole. If the plant is quite large, you may need to cut a trench through the middle of the plant and lift half of it at a time (or a quarter of it if it’s really large).

Immediately, transfer the plant to a bucket or box, and set it in a cool place until you can replant it. If the roots do dry out before you can plant, soak them in a bucket of water for an hour or so before replanting.

Recommended Stories For You

Replace whatever soil you’ve removed from your garden with fresh compost or organic matter to refresh the soil and keep it fertile.

One stem from a perennial will triple or quadruple in size within the span of one year, if properly cared for. Therefore, as you divide your perennials, split them into small sections. This will save you from having to do it again next fall, as the plant should be healthy for several more years.

As you split your plant, throw away the dead center and root sections that don’t look healthy and vigorous. Generally, it is the outside sections of the plant that appear the healthiest. Some plants can be split just by pulling it apart with your hands; others may require the use of a sharp knife or even a hatchet for tough, woody rhizomes.

When you’re ready to plant, be sure to dig a hole deep enough to keep the plant at the level in which it originally was growing and wide enough so the roots can be spread out and not need to be curled up, under or around the plant. And be sure to give enough space between plants to allow for vigorous growth. Plants need air circulation and if crowded, they will have to fight with other nearby plants for water and nutrients.

Unfortunately, there are some plants that do not do as well when we try to divide them. These include Artemesia, Dianthis, Delphiniums, Euphorbias, Foxgloves, Salvia, Geraniums, Lavender, Russian sage and Trillium. For these plants, I would collect seed and spread that around the area you wish to have these plants grow.

Being able to divide your perennials is like having your own garden center in the backyard.

Deb Babcock is a Master Gardener through the CSU Extention Routt. Questions? Call 879-0825.