Why would you use grafted plants?
Grafting and budding are used because some seed grown plants can take a very long time to flower & fruit and then may be of poor quality after all.
Budding and grafting involves joining parts of two or more different plants together in such a way that they will grow together and continue to live as one individual plant. The top part is called the “scion” and the bottom the “stock”.
The only difference between budding & grafting is the amount of material attached to the stock.
Budding is the cutting out of a single bud with a small piece of wood backing it, then joining this to the stock (as is done with Citrus plants).
Grafting is attaching a piece of stem containing several buds to the stock.
The two essential fundamentals of budding or grafting are:-
- the Cambiums (the growth layer just under the bark) MUST match up so that the sap can flow between the Scion and the stock and
- the union must NOT dry out so are sealed & wrapped until the join heals.
The reason to use grafted plants is to have a much better plant that resists LOCAL insects & diseases. i.e. the root stock used in say Victoria for Citrus plants, would be different to the root- stock used in Queensland.
This a very good reason to buy your citrus plants from a LOCAL supplier (including chain stores like Woolworths & Coles) as they NOW use Local suppliers rather than buy from a postal supply nursery from Southern states because they will use their LOCAL root stock which will be different to the Queensland root stock used.
When the top part (i.e. the part that produces fruit, a specific coloured flower and /or perfume) is selected, then the root stock (the part in their ground) is usually selected for its vigour, disease resistance & tolerance of poor soil conditions. e.g. salt ,lime, water-logging, or to make the top part more compact.
Combined citrus tree
Westringia is often used as a root stock for grafting plants sensitive to the root disease of Cinnamon fungus (Phytophthora cinnamomi)
Plants from a winter rain summer dry climate, (e.g. Western Australia), are often grafted onto root –stock species more resistant to Winter dry & Summer wet climate’s conditions. (e.g. Eastern Australia).
Grafted plants are more expensive because they need more time & expertise to be produced compared to plants grown as cuttings or from seed.
Some Grevilleas are grafted onto Silky Oak root stock (Grevillea robusta) because that root stock is resistant to most Eastern Australian conditions of poor soil.
There are a range of grafting methods that are used but all need to be practiced often, otherwise you will loose your ability to accurately match up the Cambium tissue (the water & nutrient conducting tubes just under the bark of a plant) of the top section & the root stock.
A trailing variety of a plant is often grafted onto a standard plant so that it cascades down near eye height & so is much easier to see the full beauty of that top stock.
Another vegetative propagation method is to use Micro-propagation (Tissue Culture) where a few cells at the tip of the root are taken, kept under sterile conditions and later (up to 1 year later) taken out of the flask and potted up in a pot.
These plants are then exactly the same as the parent they came from.
With this much skilled work & time delay it can easily be seen why tissue culture plants are so expensive. It is only very special & expensive plants, e.g. prize winning orchids that are worth the effort of this type of propagation.
Today’s Did You Know…?
Some citrus plants are grafted onto dwarfing root stock so that the citrus tree can be more easily grown in a back yard, or in a big pot, and the fruit more easily picked.
There is at least one commercial fruit nursery that sells plants that are grafted so that there are two or three different types of citrus on the one root stock so a person in a backyard can have 2 or 3 types of citrus fruit in a small area.