Carol Klein spreads the love by explaining how easy it is to take root cu ings
Taking root cuttings is a simple way to propagate some of your favourite plants
When you think about it, you can make new plants from just about every part of a plant. Not every plant can be reproduced in every way, but some of the parts of different plants used are seeds, leaves, stems, crowns, bulbs, cells (in micropropagation) and roots. Perhaps it’s this last category, roots, that’s most difficult to get your head round. The first time I gave it a go I was doubtful about it but when it worked, my cynicism disappeared. Growing new plants from roots has to be one of the most satisfying of all methods of propagation. It exploits an innate capacity to make whole new plants from pieces of root.
There are two types of root cuttings, and if we look at the plants in question in our gardens, it’s self-evident that we can make more by exploiting the way they grow. Do you grow Oriental poppies and have you ever tried to move them? Chances are if they’ve lived there for some time, even after you’ve moved the main plant, there will still be regrowth from pieces of root left behind. New shoots will emerge from the top of the snapped-off root.
Anyone who grows Japanese anemones will know they’re inveterate colonisers, popping up here and there, sometimes in the unlikeliest places in between paving, tunnelling under paths – nothing can halt their progress and trying to curtail their spread is a thankless task. The more skinny pieces of root that get left behind, the more anemones you’ll have. If you look very carefully along the length of one of these roots, you can see little bumps or nodules and each of them, given the right conditions, is capable of making a new shoot with its own root system. Other plants that spread just under the soil’s surface by similar means, but have thicker roots, include forms of Geranium sanguineum as a good example – these nodules are even more pronounced.
In both cases, by emulating what nature does, we can help make new plants, pot them on and decide ourselves just where we’d like to plant them.
Traditionally, this was probably a technique used by head gardeners on big estates and it would have been carried out at this time of year. Material would have been gathered over winter and the roots stored in damp sand in a cold frame. February’s the time often recommended for taking root cuttings, but perhaps the main reason for its practice at this time of year was more to do with ‘a quiet time’, with the majority of heavy winter work completed and before the press of spring tasks began. We often take our root cuttings at this time of year; it’s convenient, but when we’ve taken them at other times of year they’ve worked just as well.
In the first scenario with thick root cuttings – let’s call them ‘vertical’ – you can collect material by digging up the whole plant and severing the most promising roots or, less drastically, you can delve down close to the plant, exposing a few roots and severing those required. Then gently refill the hole you’ve made, rather than having to replant the whole plant. In both cases, cut roots into 2.5cm (1in) long pieces for reasonably thick roots, a little longer if they’re on the skinny side. Plunge them up to their hilts around the side of a pot or an individual module compartment, always ensuring that the end that was closest to the crown is uppermost.
For ‘horizontal’ roots, cut into 2.5cm (1in) to 5cm (2in) pieces, but this time lay them down on the surface of the compost, covering them with a fine layer of grit to hold them in place. Water well, then place them in a warm, well-lit place. Root cuttings will even take root outside. Make sure to wait for a few weeks after the first new shoots appear before potting them up. Good luck!
‘Growing new plants from roots is one of the most satisfying methods of propagation’