How to take cuttings: root cuttings
by Rhiannon James
Taking cuttings is a great way to turn a single plant into many more. While most cuttings come from above ground, it’s also possible to propagate some perennials, shrubs and climbers from cuttings taken from their roots. The method is really straightforward and can produce relatively large and vigorous new plants.
Root cuttings can be taken from well-developed adult plants when they’re dormant; in most cases, this will be during the winter.
The plants which can be propagated in this way include: Acanthus (bear’s breeches), Dicentra (bleeding heart), Papaver orientale (oriental poppy), Anchusa azurea (bugloss), Anemone x hybrida (Japanese anemone), Gypsophila, Verbascum, Echinops (globe thistle), Phlox, Eryngium and Limonium (sea lavender).
Lift a strong healthy plant and wash the soil off the roots.
Select young, vigorous roots, the thickness of a pencil, which are firm, plump and undamaged. Cut them off close to the crown with a sharp knife or secateurs and remove any small fibrous side roots. Don’t take any more than a third of a plant’s root system and replant as soon as possible.
Cut each root into 7-10cm lengths. Cut straight across the top and make a slanting cut at the bottom so you can tell which way around the piece of root is to be planted.
Cuttings should be planted in a 13cm pot filled with moist gritty compost. With a dibber, make holes 3-5cm apart, around the edge of the pot. Push the cuttings into the holes, sloping end down. The tops of the cuttings should be just below the surface of the compost.
Cover the compost with a fine layer of horticultural grit (this helps to keep the cuttings aerated). Place the pot in a cold frame or in a sheltered place outside, on a windowsill in a cool room or in a warm greenhouse.
In the following spring, when the cuttings have a good root system and are producing shoots, pot them up individually.