Easy Guide to Rooting Shrubs From Semi-ripe Cuttings in Autumn

Raising new plants from cuttings is one of gardening’s greatest joys. Basket plants such as Fuchsias and Helichrysum petiolare are worth propagating from semi-ripe cuttings in late summer/early autumn as are a wide range of evergreen shrubs such as Hebe, Lavandula species, Rosmarinus species, Santolina species and Viburnum tinus, as well as some deciduous subjects including Berberis thungbergii and Potentilla species and cultivars.

How to Make Semi-ripe Cuttings

Always select healthy shoots from which to make cuttings. Keep the collected material in a plastic bag out of the sun to prevent drying out. Make nodal cuttings by trimming the base of the cutting at right angles just below a node (that’s the slight swelling that occurs below a leaf joint). Prepared cuttings should have 2-4 leaves and be 7.5-10cm long.

How to Improve the Chances of Rooting

Cuttings of some plants root easily, but you can improve your chances of success by treating them with a rooting hormone. These aids contain synthetic hormones similar to those occurring naturally in plants to induce rooting. Rooting hormones are available as powders, liquids or gels. My preference is for gel formulations, because when you dip the base of the cutting in the gel it remains in contact around the stem, seals the cut tissue and supplies the necessary root promoting hormones.

Where to Root Semi-ripe Cuttings

A cold frame is the traditional place for rooting cuttings taken in September and October:-

• Replace the top 13cm of soil in the frame with a mixture of 50% fine bark and 50% coarse sand.
• Top this with a 2.5cm deep layer of coarse sand to give better drainage around the cuttings and better aeration.
• Push the cuttings into the compost up to their lower leaves and space them about 7.5cm apart.
• Water the cuttings in.
• Don’t forget to label them so next year you will know when you took them and what they are.
• Throughout autumn and winter check the cuttings occasionally and water if necessary, but never allow the compost to get too wet as this will cause cuttings to rot.
• Strong sunshine scorches the cuttings so paint the glass with shading wash.

If you haven’t a cold frame and want to root a decent number of cuttings it’s cheap and easy to make a low polythene tunnel for the purpose:-

• Choose a sunny well-drained piece of ground about 1 metre wide in the vegetable garden.
• Prepare the soil and insert the cuttings as for the cold frame.
• The tunnel can be made from hoops of wire or alkathene piping which supports 150 gauge white (opaque) polythene.

How to Treat Rooted Cuttings

Most cuttings will have rooted by April or May. Acclimatise the cuttings to life outside the propagator by gradually increasing the ventilation of the cold frame or lifting up the sides of the polythene tunnel before removing it entirely. It’ best to leave the cuttings where they have rooted until autumn before transplanting them or potting into individual containers.