What to do when your perennials start to look tired

If you have an established perennial garden that is more than two or three years old, chances are you have some plants out there that are looking tired and need attention. The window of activity is small as most perennials are best to be divided in early spring.

There are three main reasons perennials need to be divided: they may have become too large for the space; the oldest part of the plant may have died out; or growth may have become so dense that the plant is no longer blooming well. Below are some guidelines to follow in the process of division.

Unless the plant is quite small, you’ll find it’s easiest to use a garden fork or spade to lift out the entire root ball and place it on a nearby tarp.

Pry the root ball apart into two or more pieces. If the growth is too dense to pull apart, you can cut the root ball into pieces using a sharp spade, hand saw or old serrated kitchen knife. Discard any sections that are dead or have weakened growth.

Before replanting, freshen up the soil by incorporating some compost and a handful or two of granular organic fertilizer.

Replant only the healthiest chunks, putting the extras elsewhere in the garden or passing them along to friends.

Water the newly-divided plants deeply and keep their roots consistently moist for at least 2 weeks, while they are getting re-established.

Some other helpful tips on which varieties do or do not benefit from division to how often they should be split are listed below.

 

Perennials to be divided every 2-3 years in early spring:

Aster

Coreopsis

Sedum ‘Autumn Joy’

Garden mums (Dendranthema)

Helenium

Heuchera

Shasta daisies (Leucanthemum)

Garden phlox (Phlox paniculata)

Yarrow (Achillea)

 

Perennials to be divided every 3-5 years in early spring:

Bergenia

Cranesbill (Geranium)

Campanula

Daylilies

Eupatorium

Nepeta

Rudbeckia

Stachys

Veronica

 

Perennials to be divided infrequently:

Goatsbeard (Aruncus)

Hosta

Lady’s mantle (Alchemilla)

Lungwort (Pulmonaria)

 

Perennials to be divided other than in early spring:

Bearded iris (early summer after blooming)

Creeping phlox (fall)

Foxtail lilies (fall)

Oriental poppies (fall)

Peonies (fall)

 

Perennials best not to be divided at all:

Baby’s breath

Baptisia

Candytuft

Clematis

Delphinium

Euphorbia

Flax

Foxglove

Lupine

Monkshood

Rosemary

Russian sage

Trillium

Yucca

 

Happy Gardening!

 

For more ideas ask your local garden center professionals and make sure you follow us on FacebookTwitterInstagram, YouTube and Pinterest for other help tips and hints.

 

Jodi

Guest post by Jodi - Bylands Account Representative

 

Outside of work I spend time with my family, playing golf in the beautiful Okanagan, practicing yoga and of course gardening.  I like to plant annual and perennial containers. I also plant a vegetable garden every year.