An easy way to get plants for free…
If you’re new to gardening and want to increase your stock of plants, you can’t do better than root cuttings. It may not be the best-known way of getting more plants for free but it’s well worth a try.
They don’t need special aftercare like leaf or stem cuttings, large numbers of new plants can be generated and the new plants are relatively large and vigorous.
Plants suitable for root cuttings
You can’t take root cuttings from just any old plant. You need to use plants that naturally produce suckers (new shoots) from their roots, usually herbaceous plants with thick or fleshy roots.
- Acanthus (Bear’s breeches)
- Anemone hupehensis (Japanese anemone) and A. x hybrida
- Echinops (Globe thistle)
- Eryngium (Sea holly)
- Papaver orientale (Oriental poppy)
- Pulsatilla (Pasque flower)
- Primula denticulata
- Verbascum (Mullein)
Woody plants from root cuttings
For woody plants, dig down to expose part of the root system. Take roots up to finger thickness. Remove any fibrous roots and cut into 5-15cm (2-6in) sections. Then treat in the same way as root cuttings of herbaceous plants.
- Aesculus parviflora (Bottlebrush buckeye)
- Ailanthus (Tree of heaven)
- Aralia (Castor oil plant)
- Catalpa (Indian bean tree)
- Chaenomeles (Japanese quince)
- Clerodendrum (Glory flower)
- Robinia (False acacia, black locust)
- Sophora (Dwarf kowhai)
- Syringa (Lilac)
- Campsis (Trumpet vine)
- Passiflora (Passion flower)
- Solanum (Chilean potato vine)
When and how to take root cuttings
- Take root cuttings when the plants are dormant, from late autumn or early winter.
- Choose large, vigorous clumps to propagate. Lift the plant and wash the roots.
- Select young pencil-thick roots and cut them off close to the crown with a sharp knife.
- Remove no more than one-third of the root system, then replant it as soon as possible.
- Cut off the thin root end and remove fibrous lateral roots.
- Cut each root into 5-10cm lengths, with a horizontal cut at the top end and an angled cut at the bottom.
- Plant in pots filled with equal parts peat-free compost and gritty sand or perlite.
- Insert the cuttings 4cm apart so that the top of the root is just below the surface of the compost. Top dress with a 1cm layer of grit.
- Water the compost lightly and place pots in a cold frame.
- In spring, when there are signs of growth, pot up and grow plants on and plant out the following year.
Choosing the right sort of roots
Perennials such as Japanese anemones, Campanula and Phlox, have thinner roots, so they need longer root sections of 7.5cm-12cm to contain enough food reserves. Lay them horizontally, 2.5cm apart, cover with 1cm of compost and topdress with grit.
Problems with root cuttings
No roots to cut: Lift older plants in autumn and cut off top and root growth to within 5cm–10cm of the crown. Propagate from young, vigorous roots the following autumn.
Plants that hate root disturbance: Some plants (Eryngium and Pulsatilla) resent root disturbance. In spring, place container-grown plants on a 15cm layer of sand in a box and sever roots produced in the sand in autumn.
Preventing rot: Take care not to over-water.