top of page

Jobs for the month - divide your herbaceous perennials

This was job Number One on our list of Top 10 things to do in September. You can find that list here if you missed it:

Earlier this year we sourced and planted some herbaceous perennials for one of our regular customers. She wanted some plants that would attract wildlife so amongst the selection we planted we included a few Achillea filipendulina ‘Cloth Of Gold’. The thing is she thought that they looked too much like ragwort so this week we found ourselves taking them out.......

Normally we'd divide Achillea between March and May - and only divide them after they've been in the ground for 3 years or more - but as we knew that the plants weren't wanted we thought we'd use the opportunity to show you how easy it is to divide your herbaceous perennials.

Before we do that though let's make sure we know what a herbaceous perennial actually is! Now the RHS tells us that:

"The term ‘perennials’ is used loosely by gardeners to indicate those plants which grow in beds and borders, which are not trees, shrubs or bulbs. They are the ‘summer colour’, the ‘border flowers’ and make up a ‘flower garden’.

Herbaceous perennials have stems that die back in late autumn and early winter. The roots then survive below ground during winter, shooting again in spring. Well known examples include delphinium, geranium, miscanthus (an ornamental grass) and sedum".

There are of course other varieties of herbaceous perennials and all can be used in different ways in your garden and can be pruned slightly differently - from cutting back in the autumn as the plants die or giving those that flop over earlier in the season the "Chelsea chop" to produce plants that are more likely to stand up straight and tall!

Perennials can also be propagated in different ways - from taking cuttings, to collecting seeds, to division. However the purpose of this article is to talk about division, so here we go. This is all there is to it:

  1. Using a garden fork, gently lift the plant. Work from the centre of the plant so as to limit damaging the roots.

  2. Shake off as much soil as you can so that you can clearly see the roots.

  3. Plants, like Ajuga, often produce new plants. These "babies" can simply be teased out and planted up into pots until they've matured.

  4. Plants such as Heuchera and Hosta have roots that are smaller and more fibrous. These can be lifted and pulled apart gently. The small clumps can then be planted up.

  5. However larger perennials with more fibrous roots will need to be loosened by using two garden forks. Using them as levers to loosen and break the roots and lift the plant, the sections can then be divided further as necessary.

  6. If the plant has a woody crown or fleshy roots then a sharp knife or spade might be needed to divide the plant. It's always a good idea to try to produce clumps containing 3 to 5 healthy shoots.

So back to our Achillea 'Cloth of Gold'. Firstly this is what they look like in our garden - where they're now a few years old.

This is a similar plant that was only planted up earlier this year. Using our hand trowel we've loosened the plant and started to tease it out of the ground.

Here and after we've had a go at dividing the roots with the hand trowel we've switched tack and used our secateurs to cut into the roots.

Having done that we have the beginnings of 2 new plants..... well, 3 actually - that white'ish root with the start of a new leaf is something we don't want - thank you very much! It's bindweed so we'll get rid of that! You can see that although a relatively young plant the crown is already quite tough and woody.

And then we pot them up in some of our own potting compost. We cut the old growth down so that the new plants will be encouraged to divert all their energy into developing new strong roots and not into what's going on above the surface - which we know is about to die back at this time of the year anyway.

And that's about all there is to it. We've now got 5 plants from 2 that were no longer wanted or loved. All we need to do now is pop them in the greenhouse keep them watered and hopefully in the spring we'll have some new plants that we'll be able to add to ours, or someone else's, herbaceous border.

Next up will be lifting our remaining potatoes and having a wander to see what seeds we can save for next year - all jobs for the weekend with the Truglets - if the weather holds!

If you have any questions or want to get in touch then you can contact us through our facebook page, at or on 07734 365028.


bottom of page