Propagation

Propagating, to obtain new cacti and perhaps the only way to increase the presence of rare and endangered species, is important.

There are several ways of propagation namely :

¤ Raising from Seeds
¤ Cutting / Dividing plants
¤ Grafting

Raising from Seeds

Most cacti are not raise from seeds as it often takes a much longer time to grow. Besides, other than commercial seeds, it is difficult to collect seed from most species due to the fact that only adult plants bear fruit and they don’t do it in most climate. However, in the case of plants that bear no branches or shoots suitable for cuttings, seedling will be the only way.

Small seeds can be sprinkled over the soil surface but larger seeds need to be pressed down into the soil for about twice their own dimension. Some ignored spacing between seeds. Yet, by keeping about 1-2 cm between each seed, it ensures some room for them to grow (although some seeds may not develop).

Moist soil for seedling is required. Such condition should be maintained for a least 2-4 weeks with the help of plastic bag covering the whole pot during germination. Remember, no direct sunlight! Seedlings may be scorched. For about a week time, seed leaves will appear (depends on species). And once most seed leaves have developed, plastic bag has to be removed to improve ventilation.

During a period of several months to a year (depends on species), they are the most fragile. Care and attentions is much required.

Cutting / Dividing plants

Generally, branches or basal shoots are used for cuttings. Such branches or shoots are removed from the parent plant using sharp knife and care is required to prevent damage to the parent plant which results in disfigure or in danger of dying. Cuttings should not be buried deep into soil. If it is likely to fall, support it with stick.

More care is required until the cutting has put down roots after 3-12 weeks depends on species. During this period, place the cutting away from strong direct sunlight and water sparingly to keep the pot just damp.

Grafting

Grafting was originally a propagating technique for difficult and slow-growing cacti. Certain species with weak root systems take long time to grow and may not survive the climate. In such, these species are grafted on to the root stock of a more vigorous species and the growth rate can be increased by a few times. e.g. a low-growing cactus may took 4 years to grow into desired size, but it only took about one year to grow into the same size using grafting.

Basically, there are 2 types of grafting namely : Split-grafting & Flat-grafting. Split-grafting is less commonly used compared to Flat-grafting. This may due to the fact that Flat-grafting has a better result and most cacti are globular in shape that is not suitable for Split-grafting.

Split-grafting
(1) Slice off the top of a vigorous root stock which used as a base for grafting.
(2) Make a vertical cut of 1-2 cm deep from top through the central core tissue of the root stock.
(3) Select a healthy branch/shoot (scion) for grafting.
(4) Trim the lower part of scion tapered to fit the split of the root stock.
(5) Wedge the scion into the split of the root stock and ensure both core tissues make good contact.
(6) Bind both the root stock and scion to hold them in place with thick string (2-3 mm thick).
(7) Leave to grow in bright, airy site.

Flat-grafting
(1) Slice off the root stock horizontally about 3 cm from the top to expose the core tissue.
(2) Remove some of the skin around the edges of the stock to ensure both core tissues will make good contact.
(3) Cut off the scion horizontally to reveal the core tissue.
(4) Place the cut surfaces of both scion and root stocks together and rotate the scion to remove air pockets that trap between the two tissues’ surface.
(5) Fasten the scion and root stock together with rubber bands and allow to grow.

The main difference between Split and Flat grafting is that : Split-grafting is usually done with a root stock diameter of less than 2 cm whereas Flat-grafting will requires a root stock of 3 cm or more.