Dividing perennial plants

Herbaceous perennials are those plants where the top growth dies off in the autumn leaving roots and the crown of the plant to survive the winter and throw up new stems the following spring.  Many are easily divided to provide extra plants and rejuvenate an old clump where flowering is poor and spring is a good time as the soil warms up and light levels increase.

Herbaceous perennials photoWith division, like cuttings, the new plants are identical to the original and you do not get the variability of propagating by seed.  Some modern cultivars and many with double flowers do not set seed easily and so division is the easiest option if you want to increase your plant stock or share plants with gardening friends and neighbours.  How you go about dividing a plant depends on the root structure but always involves digging the plant up first, so get ready with a bucket and some fresh compost to protect the cut sections from drying out until you plant them up when the operation is complete.

  • Plants like hardy Geraniums or Heuchera where stems or rhizomes run underground are simply cut with clean secateurs or a sharp knife making sure that you have both root and shoot on each section.
  • Plants with a mass of small roots like Daylilies (Hemerocallis) are split by pushing two garden forks into the clump back to back and levering them apart.
  • Plants that form large woody roots like Peonies require more force and are best sliced in half with your boot on a sharp spade.  Cut into two or more sections each with strong buds visible on the top.   Always make sure that the clump is stable on the ground first to avoid a trip to A&E for you instead of the plant.

Whatever the method of division you need to have roots and shoots or large buds on each piece that you replant. Usually you get enough new vigorous plants from round the edge of the clump to retire the old central section and still have some spares to pass on to admiring friends or a charity plant stall.

Happy Gardening from Alison

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