Divide Your Hostas, Perennials, Bulbs and More to Clone Your Favourite Plants from Your Garden

Plant reproduce naturally, but when a gardener wants to clone a parent plant, they turn to propagation to get the exact same plant characteristics in the offspring. One of these methods of propagation is plant division.
Division is used for several reasons. Gardeners looking for an exact replication of the parent plant will get good results every time with division, unlike growing from seed. A plant that has outgrown its space, or is thinning in the centre and needs some rejuvenation are all good candidates for division.

European peony or Common peony (Paeonia officinalis)

European peony or Common peony (Paeonia officinalis)

There are a few types of plants that can be divided:

  • perennials that form a clump of shoots below the soil surface (hosta)
  • perennials with tough woody crowns (peony)
  • bulbs (tulips)
  • tubers (dahlia)

When to divide plants

It is best to divide plants when they are mostly dormant, generally from October to April. Plants that bloom in summer and fall, divide in spring. For plants that bloom earlier in spring and early summer, it is best to divide them in the fall. You want to avoid dividing plants during their active or presentation season. Don’t divide during frost or periods of drought.

Before you divide your plants

Perennials that have almost lost all their leaves in fall can be dvidided, and it helps to cut back their foliage if there is any left. Water plants well before dividing if the soil is dry.

Dividing clumping perennials

Siberian Iris

Siberian Iris

Discard the older, woodier parts of the plant in the middle and use the younger outer growth for replanting. You will notice Lilies and Iris have this pattern of older, woody growth in the centre of the clump.
Divide the plant into portions: either half, thirds or quarters of the original plant. Each portion should have enough buds and roots to support new growth.
For portions that you want to grow in pots, having a clump with two to three buds is sufficient. This is a great way to make some extra income from your garden’s lush growth. Hosta plants are often shared among gardeners this way.
For immediate replanting in the garden bed of divided portions, use clumps with 4-6 buds for quick re-growth and decent size.
It is good to check the crown of the plant for any unwanted insects, such as weevil larvae.

Dividing plants with tough woody crowns.

Hellebore Christmas Rose

Hellebore / Christmas Rose

Astilbe, Kirengeshoma, Hellebores and Peony are all examples of plants with tough woody crowns. The trick here is to dig the entire root out of the ground. Next, wash off the soil to expose roots and buds.
Cut the crown into pieces that each have buds, crown and roots.
Dividing woody perennials is best done just before spring to prevent rot.

Dividing bulbs, corms, tubers and rhizomes

Tulip bulbs that have matured into multiple bulbs can be dug out and divided into individual bulbs. Eventually these will grow to larger sizes and produce more plants. Garlic is propagated this way as well. Every year, the bulb develops into a cluster of bulblets, what we call cloves, which can be divided and used as individual plants for next year’s crop. Other bulb plants include Dahlia, Canna lily, Allium and many more.
Potatoes can be divided with a knife by cutting an individual potato, or tuber, into sections. Each portion should contain an eye, or bud, for growth. Other tuber plants include jicama, yam, Jerusalem artichokes and cassava.

hosta northern halo

Hosta ‘Northern Halo’

Any plant that spreads by underground rhizomes can be divided in this way as well. Canna, Convallaria or Lily of the Valley, Flag Iris, Several Ferns, Alstroemeria and Zantedeschia grow from rhizomes. Several common kitchen spices also have rhizomes Ginger, Turmeric and Galangal are a few. Using a knife, cut a portion of the root that has upright buds or stems and roots attached to the same piece. It is really easily to produce more plants for your garden this way, or to share with likeminded friends. Keep this in mind when you’re trying to get rid of weeds that grow by underground rhizome. Each piece of root that is left behind has the potential to grow into a new plant. Thoroughness is best in this case!
Dividing plants is an economical way to expand your plant collection, share with friends and neighbours or to propagate plants for a plant sale to fund some new purchases for the garden. Share your experiences in the comments below. Happy digging and dividing!