Softwood cuttings are mostly used for propagating hardy and tender perennials like Aubrieta, Pelargonium, Petunia and Verbena.
This technique can also be used for a wide range of mainly deciduous shrubs, such as Buddleja, Fuchsia, Hydrangea, as well as some trees such as magnolia.
According to the RHS softwood cuttings have the highest rooting potential of any stem cutting and provide the best chance of rooting species that can be difficult to propagate.
Most softwood cuttings are taken in spring and early summer, from the tender new growth of the season.
If potted by mid-summer the cuttings will develop sufficient roots to survive the winter, otherwise pot up in the following spring.
- Cuttings from young plants root more easily.
- Key tip: heavily pruning older plants can stimulate new growth that will root quicker than the old growth.
- Soft plant material loses moisture rapidly, so care needs to be taken to keep conditions sufficiently moist to prevent wilting.
Gathering cuttings material
- Collect material early in the day when it is full of water (turgid).
- Collect non-flowering shoots, as they will root more readily
- Remove up to 10cm (4in) of shoot, cutting off the material neatly above a bud on the parent plant.
- Place the cuttings material in a clean plastic bag with a label. Store the bag of material in the fridge if you cannot prepare the cuttings immediately.
Preparing nodal softwood cuttings (from advice published by the RHS online).
Most softwood cuttings are nodal, ie. cut at the bottom just below the leaf joint or node, where there is a concentration of hormones to stimulate root production.
- Using a sharp knife trim below a node to make a cutting about 5-10cm (2-4in) long
- Remove the lower leaves, pinch out the soft tip and dip the base of the cutting in hormone rooting powder or liquid
- Make a hole for the cutting in a a container of cuttings compost using a dibber (a clean blunt stick) and insert the base of the cutting with the first pair of leaves just above the level of the compost
- Label the pot and water it from above to settle the compost
- Place the pot in a closed propagator case with bottom heat of 18-24C (64-75F). Covering with a plastic bag and placing somewhere warm will suffice if no other equipment is available, but remove the bag to ventilate the cutting at least twice a week for 10 minutes. Commercial nurseries use mist units to provide constant humidity
- Cuttings should be placed in good light but not direct, scorching sunlight. Covering with fleece will help diffuse bright sunlight
- Ensure the compost is moist until the cuttings are well-rooted which takes about 6 to 10 weeks
- Once rooted, harden off the cuttings for about two weeks and pot them on individually. Covering with fleece or gradually increasing the ventilation of plastic bags or propagators will allow the soft leaves to develop a robust water-proof cuticle so that they can survive in lower humidity environments
- Remove any dead, rotting, dying or diseased material at least weekly
Some hard to root plants such as Rhododendron respond well to wounding, removing a thin slice of bark near the base of the stem and then dipping the wound in hormone rooting compound. Others, such as Acer palmatum, Cotinus, Lonicera, Jasminum and Sambucus, can be removed from the parent plant with a heel, pulling off the stem with a ‘tail’ of bark from the previous season’s growth. The heel is then dipped in hormone rooting compound.
Preparing basal softwood cuttings
These are similar to nodal cuttings except they are taken from clusters of young shoots at the base of herbaceous plants in spring.
- This technique is suitable for Aster, Chrysanthemum, Delphinium, Lupin, Phlox and Salvia.
Select sturdy shoots 7-10cm (3-4in) high with the leaves just unfolding.
- Using a sharp knife remove them as close to the base as possible, including part of the woody basal tissue.
- Then treat as nodal cuttings.