Propagation by Cuttings
by Lionel Theron
There are many types of plants that may be propagated by stem cuttings and it is an easy and inexpensive way of obtaining new plants. It must be realized that, as far as bonsai is concerned, it does not provide quick ready bonsai but material suitable for turning into bonsai in due time.
Young plants, like young animals, usually grow much more vigorously than mature ones. This means that plants grown by seed or young soft wood cuttings grown under ideal conditions may well overtake older hardwood cuttings. Taking a cutting which is already mature may not be a short cut time wise but it is possible to use a particularly attractive branch to develop into nice bonsai material.
These are usually taken when plants commence growth either in spring or sometimes later in the season. As different plants may commence growth at different times it is not possible to give exact dates but guidelines do exist.
There are different kinds of cuttings, namely: nodal cuttings, heel cuttings and mallet cuttings.
When making nodal cuttings:
- They should be cut reasonably close to the node leaving the node intact so that it does not rot in the long part of the stern left on the cutting.
- The cutting should be small as large cuttings tend to wilt and collapse before cell division can commence.
- The reason why cuttings die before rooting is that they lose moisture through transpiration before growth can commence. It is important to reduce the leaf area as transpiration occurs through the stomata on the leaves. Remove most of the leaves and cut large ones in half. Never allow leaves to come into contact with the soil as this will cause them, and subsequently the cutting, to rot.
- Most cuttings should be planted soon after they have been made. Dip the base of the cutting in a rooting hormone preparation as this will ensure a higher percentage of successful rooting.
Plant in a coarse and fast draining medium such as coarse river sand. A little moisture retentive material such as peat or perlite may be added to the mix. Place the cuttings in a position where moisture loss through transpiration is not too high but do not place them in the dark, the whole principle of plant growth is dependent on the energy der i ved from light (photosynthesis). One may use some method of creating a miniature greenhouse effect but bear in mind that the fungus that causes damping off loves a nice snug atmosphere without air movement. Damping off can, to an extent, be treated by spraying with the fungicide Benlate.
It is usual for cuttings to root from the area of the cut and from nodes and it is usual to obtain better results if one has planted at least one set of nodes under the growing medium. Never allow cuttings to dry out as even if they have started rooting they will die.
MEDIUM & HARDWOOD CUTTINGS
Medium ripe wood cuttings and hardwood cuttings may be taken later in the growing season but they generally need more time to take root.
Sometimes cuttings can be struck in water but they may fail when transferred to soil for several reasons, it is better to start cuttings in a medium such as has been described.
Cuttings of conifers are also highly successful. If in doubt try a cutting, invariably you will have success!