How to divide perennials

Learn how to divide the perennials in your garden.
Dividing perennials

 

Why do you need to divide perennials?

Clumping perennials are divided for several reasons

  • To replenish the plant (as they grow and multiply, the plants in the centre can become overcrowded and starved of nutrients, light and water).

  • For propagation (turning one plant into many, although be careful, the smaller your clumps, the longer they will take to mature and flower).

  • Overcrowding (as plants spread, they can outgrow the area you allocated and need to be reduced in size so they fit back into their area of the garden).

How do you divide perennials?

This method shows you just how easy it is to divide clumping perennials in your garden.

  1. Using a fork and/or spade, dig around the clump and lift, trying to minimise damage to the roots and neighbouring plants

  2. Clear away any dead foliage, weeds or damaged roots

  3. Find the middle of the clump. When you look closely, you can see where the plant can naturally be divided

  4. Cut the clump in half with a sharp spade or knife. Some plants will pull apart easily if they are planted in a loose, sandy soil

  5. When you have finished, you will have several healthy looking clumps, ready to be replanted into the garden

  6. Plant into freshly prepared soil enriched with aged compost and manure. Apply a seaweed solution after planting and treat as you would any newly established plant

Tips and tricks for success

Bearded Iris

Select only plump rhizomes, discarding any that appear shrivelled or unhealthy. Cut foliage back to about 10-12cm in an arrow shape before replanting.

Dahlia

These benefit from regular division, but wait until late winter when the plant completely dies down to the tuber. Be sure to get a segment of stalk with active buds.

Salvia

Clumping salvias (like Mexican sage) can also be readily divided. Avoid disturbing woody species.

Grass

Many grasses, like Miscanthus benefit from regular division, however some, like Stipa gigantea, sulk after division.

Herbs

Spreading herbs like mint, thyme and oregano benefit from regular division to keep plants productive and healthy.