Multiplying your shrubs

By Melanie Mathieson
Gardening Guru

Have you ever wished that like your perennials that you could divide your shrubs and plant them in other places in your yard? Well you can try to clone offspring from the parent shrub by taking a semi-ripe cutting. A semi-ripe cutting is taken from this year’s growth where the tips are new and have tender growth so you have do this later in the growing season after new growth has occurred. The lower part of the branch is older and harder growth which will not work with this method. This method of propagation is common for most deciduous shrubs (not evergreen) but success may vary from variety to variety. Some examples of shrubs that will propagate with this method include mock orange, lilacs, fruit trees, potentilla, weigela, hydrangeas, roses, etc., and woody stemmed house plants.
The best time to take a semi-ripe cutting is normally in mid to late summer once the new growth is obvious on the shrub. The cutting, for the first month or so, will need to be shaded from direct sunlight, but in a warmish environment - a cold frame or propagating case (like a mini- greenhouse which is available through garden supply stores) is ideal.
STEP 1
Take the cutting from this year’s growth. Select a shoot where the tip is soft new growth, but the lower part is harder older growth. Using a sharp knife, take a cutting 15-20 centimetres (6-8 inches) long. If possible, select a shoot which has no flowers or buds on it. Remove any leaves from the lower part of the shoot and cut it immediately below a leaf joint (where the leaf meets the stem). Cut off the soft new growth at the top of the shoot just above a leaf joint. The cutting should now be about 5-10 centimetres (2-4 inches long).
STEP 2
For each cutting, fill an 8 centimetre (3 inch) pot with potting compost. Dip the base of the cutting in hormone rooting powder. You can buy hormone rooting powder at your local nursery supply store. It is in a small container (about the size of a medicine bottle) near the fertilizers. Make a small hole in the compost and insert the cutting into the hole to about a third of its length. Firm the compost down around the cutting. Water well.
STEP 3
To prevent the cuttings losing too much water, place the pots in a small propagator (like a mini- greenhouse which is available through garden supply stores) with the vents closed. Alternatively, cover each pot with a plastic bag kept off the cuttings by wire hoops inserted into the compost. Place the cuttings in a warm, draught free place which is always out of direct sunlight. A propagator is ideal or against the house wall.
STEP 4
The cuttings will develop roots in a month or so. At this stage, remove the plastic bags or propagator in order to harden them off over a week or two to the normal weather. During the winter, the plants need the protection of a cold frame or unheated greenhouse. The plants can be planted in their final positions next spring.