Abutilon pictum ‘Gold Dust’
Grafting is usually done when one plant is highly valued but, for one reason or another, is difficult to grow. The difficult plant is induced to grow on the stem of a close relative which grows more easily. The problem may be that a particular plant cannot be raised true from seed (as in some fruit trees) or because it makes a poor root system and would be better off growing on the stem (and therefore the roots) of another plant.
Some cacti are grafted on to other suitable cacti for the second reason. The almost scarlet body of the much admired Gymnocalycium mihanovichii (called Red Top or Ruby Ball) has virtually no chlorophyll (green matter) and cannot survive on its own. It can, however, thrive when it is grafted on to a green basal stock of Echinopsis, for example, when the stock (base) has healthy roots and does all the work of processing the vital plant food. Popular cacti to use as stocks include Pereskia, Cereus and certain species of Opuntia.
Instructions for grafting cacti
- Gently remove the top or, better still, an offset at, the plant to be grafted.
- If an offset has been removed, make a flat cut across its side. This is die face of the scion which will be joined with the top of the base plant or stock.
- Using a sharp knife, trim the top edge of the base plant or stock, so that it fits as neatly as possible the scion to be grafted on to it.
- Place the scion on the stock. The fit should be as neat as possible, and the scion should not ideally overhang the stock. Trim the (no parts again if needed.
- Many cacti are produced by grafting.
- With a sharp knife cut off the top of the plant that is to become the rootstock to the point where you want to make the graft. The cut should be in relatively new tissue, not woody stems or toughened bases.
- Next cut off the section that is to be used as the scion. Ensure that both cut areas are roughly the same size – ideally the scion should not overhang the stock.
- The cut surfaces of both plants must fit closely together and this will only occur if both are correspondingly flat.
- When handling cacti it is usual to allow cut parts to dry out, but in the case of grafting, it is essential that the two parts be fitted together as soon as possible.
- Once a good fit has been found, secure the two parts together with strands of broad raffia or twine, taking the material over the top of the scion and round the base of the pot.
- Make a firm, but not overtight, tie. Elastic bands can also be used but they must not be so stretched that they dig into the tissue of the scion.
- Sometimes the union can be pinned with a stout cactus spine to skewer the two sections firmly together. This method does, however, mark the parts.
- A callus will form to unit the two plants. It is vitally important that the two sections should not be jolted or knocked while the delicate operation of growing together takes place.
- Stand the pot where it will nol be knocked, in a warm place and in good light (not hot summer sun) whilst the two grow together. Water the stock sparingly during the period of union but do not feed.
- Very often you will be able to see that union has taken place when corky tissue forms over the wounds. Also, there may be obvious signs of new growth on the scion. When a firm union has been made, take off the tie and treat as one plant.
- The early spring is the best time of year for grafting but it can also be done during most of the summer and even in the early autumn months.
The base, or stock, stays in its own pot of compost. The part that is grafted on to the stock is called the scion. For the union of the two plants to be successful the plants must be nearly related and compatible. The wounded parts of each plant form a callus or thickened piece of tissue, and when the calluses unite the two plants can grow as one. It’s as simple as that. Grafting cacti is a relatively easy exercise as both stock and scion are soft and easily cut, they callus quickly and soon become one entity.
The process may seem complicated but, with a little patience, cactus offsets can be grafted with great success.
Good results from grafting
Grafting is the technique of joining a section of one plant to another plant of broadly the same family and inducing the two parts to fuse together and grow.
Split grafting
Once cacti enthusiasts have become proficient at growing these plaints, many then turn to grafting and split grafting of cacti. The stock of a Selenicereus is often used for Christmas and Easter cactus. A ‘split graft’ is used with this type of material. The stock is beheaded and then a split (cut) is made about ½-3/4 in down the centre of the stock. A section comprising 2 or 3 segments of Christmas or Easter Cactus is then gently pushed into the split and the join wrapped in broad raffia to make close contact until tissues join together. Commercial growers find grafting a quick way of increasing rare plants as they can use very small sections of the scion. They usually agree that this method of propagating is up to ten times faster than trying to grow plants on their own roots although some purists disagree heartily with this method!
