Dividing Perennials In The Fall
There are 3 great reasons to divide your perennials in the Fall.
Let's discuss when and how to divide your perennials.
For more information about fall garden care, visit our advice page.
Goal 1 : To control the size of plants
Many perennials, such as black-eyed susans, can grow into a bigger and
bigger size of clump and soon start to take over your garden. The best way
to prevent this from happening is to divide the clump into smaller sizes and
discard or give away the extra pieces.
Goal 2: To rejuvenate old plants
As some perennials age, you may see that some clumps will have started to
die out in the middle. Flowering performance has declined. The clump
may have become congested, or the roots old and woody. Soil nutrients
have been exhausted around the clump. Signs of this might be stunted
growth, yellowish leaves or lack of bloom. Dividing and moving to a new
location is a wise idea. Sometimes simply fertilizing the plant will make it
Goal 3: To propagate more plants
Dividing perennials is an easy and inexpensive way to increase the number
of plants in your garden.
GENERAL RULE OF WHEN TO DIVIDE
Divide spring and summer flowering perennials in late summer or fall.
Divide fall blooming perennials in early spring
For more information watch the above video.
AVOID DIVIDING THESE VARIETIES:
Bleeding heart (Dicentra)
Butterfly weed (Asclepias)
Christmas rose (Helleborus)
Gas plant (Dictamnus)
Oriental poppy (Papaver orientale)
HOW TO DIVIDE PERENNIALS BY MORI GARDENS
1When possible, plan to divide your perennials on an overcast day with showers in the forecast. This will greatly help the plant recover from the roots being damaged. Dividing perennials on a hot sunny day will dry out the roots much quicker causing great stress on the plant. It would also be helpful to thoroughly water the plants a day prior to dividing.
2When dividing in the spring, wait until new shoots are about 1” tall. If dividing plants in the fall, prune plants back to just a few inches tall.
3Using a spade or garden fork, dig into the soil about 4”-6” beyond where the shoots emerge. Dig all around the clump then pry up on rootball.
4Lift out the entire clump as completely as possible and sit it on top of ground or on a tarp.
5Remove any loose soil from around the roots.
6Using a sharp spade or knife, gently cut through the roots, dividing clump into as many pieces as desired. Each division should have at least 3- 5 vigorous shoots and a healthy supply of roots. If the centre of the plant has died out, divide the living, outer portions into smaller clumps and throw out dead, centre portion.
7Enrich the soil in the new planting areas with compost, composted
manure or triple mix before planting new divisions. Fertilize new
plantings by scattering a handful of bone meal in the bottom of the
planting hole. Bone meal is high in phosphorus which will help stimulate
8Remove any loose soil from around the roots.
DIVIDE ONLY EVERY 2-3 YEARS
Blanket flower (Gaillardia)
Lamb's ears (Stachys)
DIVIDE ONLY EVERY 3-4 YEARS
Bee balm (Monarda)
Black-eyed Susan (Rudbeckia)
Purple coneflower (Echinacea)
Siberian iris (Iris sibirica)
If you have questions contact our Mori Gardens team.
We're here to assist in your garden needs from Dream to Enjoyment.