Perennials you should divide in the spring

Fear can take over the novice gardener when it comes to digging up their flowers and cutting them in half, at least it scared me the first time.  It may sound cruel, but it’s actually a good thing to divided perennials about every three years.   By dividing and replanting perennials, you give the flowers more room to grow while at the same time, you are increasing the flower power of your landscape with new flowers from the dividing process.

Most perennials can be divided at different times of the year.  For instance astilbe can be divided in spring or fall, and coreopsis can be divided in spring or summer.  When it comes to perennial flowers that can tolerate dividing in spring and summer or fall, I like to go with the spring option.  Aside from the fact that the plants are easier to divide when they are at their smallest (the spring), I like dividing plants as needed in the spring because my whole garden is then starting out with a fresh face. 

Perennial Flowers That Can Be Divided in Spring

All the following perennials that have been in the ground at least three years can be dug-up, divided, and replanted at the timeframe noted:

Early Spring.  Artemisia, astilbe, bee balm, blackberry lily, black-eyed Susan, campanula, coreopsis, daylily, delphinium, garden mum, hosta, lay’s mantle, lily of the valley, New England aster, obedient plant, purple coneflower, salvia (divide every 6 years), sedium, yarrow.
Early spring clump of astilbe
about 6 inches high and 12 inches wide.  
It’s ready to be dug up, divided and replanted.
Late Spring.  Bleeding heart, brunnera.

Dig and Divide

Before digging up the plant, decide where you want to plant the cutting, and dig that hole first.  Then, using a spade, dig a circle about six inches out from and around the plant you want to divide.   Lift the plant ball with the spade or a shovel.  I like to place the plant ball on a tarp, making it easier to tote the divided portion of the with its soil remnants to its new location.  You can, however, just place the whole ball on the ground.

Use a garden saw or large knife to make a vertical cut through the center of the root ball.  If there’s a fisherman in the family and they don’t mind, a fish gutting knife will work.  After cutting into two sections, replant and water.   Remember when transplanting to place the “new” plant in the proper sun or shade level.  Water daily for the first few couple of days after transplanting. 


The list of flowers shown above is of common perennials but the list is not all inclusive of every flowering garden perennial.

© Barbara Raskauskas