Gardening

Grafting: all you need to know about this horticultural technique


The technique of grafting is, along with that of cuttings, one of the main multiplication techniques for trees and shrubs.

By following this guide, you will see that performing a transplant is not that complicated and can be done by everyone.

  • What is grafting?
  • The conditions to be met for successful grafting
  • What are the grafting techniques?

What is grafting?

Definition

Before going into more detail about the grafting, it is important that you know a few specific terms.

  • Subject or rootstock: as its name suggests, this is the plant that will serve as support at the transplant. When the latter has set, the roots of the rootstock will provide the necessary nutrients for the scion.
  • Graft: section of a plant (often a branch) intended to be fused with the rootstock in order to reproduce the species or cultivar from which it is derived.
  • Cambium: plant tissue placed just under the bark. You can see it by gently scratching the bark and discovering a thin light green film. It is the cambium which is at the origin of the roots of cuttings and layering and which allows the fusion of a graft on a rootstock.

You will understand, grafting therefore consists of reunite two healthy plants to make one.

What is grafting used for?

Transplant is a method that allows multiply plants that are impossible to reproduce by seed or cuttings. It also allows rejuvenate a tree or shrub that would be unproductive (whether fruiting or flowering).

The interest of grafting is to combine the advantages of both elements : vigor and resistance for the rootstock and aesthetics or fruit production for the scion. For example, roses are grafted onto the rose hips; the cherry tree, on the other hand, is associated with the cherry or false cherry (Prunus mahaleb).

What do i need for grafting?

The equipment necessary for performing a transplant is fairly basic and can be found in all garden centers. You will therefore need:

  • of a graft (kind of curved knife) well sharpened and disinfected;
  • raffia;
  • grafting putty or wax.

When to perform a transplant?

The grafting period differs depending on the technique used. But in general, the operation is carried out at spring.
To prepare the rootstocks, it is advisable to remove the subjects winter ; excluding frost periods. They are then gauged in cool soil and ideally placed along a palisade or north-facing wall. The aim is to delay the re-vegetation as much as possible in order to keep the buds intact until the time of grafting. This process is called "stratification ».

The conditions to be met for successful grafting

To put the odds on your side and allow your transplant to take hold, you must follow certain rules:

  • The scion and the rootstock must be healthy.
  • To avoid possible contamination, the graft must be clean and if possible disinfected.
  • Plants to be grafted must be compatible. In general, it is better to choose plants from the same family or the same botanical genus.
  • Whatever technique is used, the cambium layers of the scion and rootstock must be superimposed for the transplant to take.
  • When the transplant has taken, remove the ligature who kept it going. This way you will avoid a strangulation bark that would make it fat.

What are the grafting techniques?

Approach graft or buttress graft

This type of grafting consists in uniting two subjects to each other while they are both in the ground (or in a pot). To achieve a graft by approach, you have to :

  • Take a strip of bark from the scion and rootstock. Each should be the same size and both cambium layers should be uncovered.
  • Apply the two wounds one in front of the other, making the cambia coincide well with each other.
  • Using raffia, tie off the graft and cover it with graft putty.

The "grip" is generally done after two months. At this point, cut off the top of the subject above the graft site. Then repeat the operation for the graft, but cutting below the graft point.

This technique is to be carried out in July, when the sap circulation is active.

Escutcheon or bud grafting

This type of transplant is the most used for multiplication of roses and shrubs. Budding is practiced by july to august (even September). To be successful, this grafting is carried out as follows:

  • On the branch of the scion, take an eye (bud) with its bark and its petiole. Next, cut the leaf blade (wide, flat part of the leaf) and check that there is no hardwood under the escutcheon.
  • Make a “T” shaped cut on the rootstock.
  • Lift the bark on each side and insert the escutcheon.
  • Tie the whole thing with raffia; without applying grafting putty.

If the transplant is successful, then the petiole should drop off on its own in October – November. At the beginning of the following spring, you can cut the subject above the graft point.

On the other hand, if the petiole turns black, dries up and does not fall off, then the graft will have failed.

Slot grafting

This technique should be performed at early spring ; just before the resumption of vegetation. As with budding, a cleft graft requires several steps:

  • Cut the rootstock horizontally so that only the foot is left.
  • Using a sharp (and disinfected) billhook, split the subject to a height of 4 to 5 cm depending on its diameter.
  • Hold the slot open by inserting a wedge into it.
  • Select the grafts so that they are 8 to 12 cm in length and especially that they have 3 buds.
  • Bevel each graft at its base and on both sides.
  • Insert delicately the grafts by making the cambium layers of the subject and the grafts coincide.
  • Remove the wedge and tie the graft with raffia.
  • Apply mastic to be grafted on the exposed parts.

Crown graft

This kind of grafting is mostly used for regenerate an unproductive adult tree and at the same time allows reconstitute the architecture of the tree by rejuvenating its main branches.

For a better recovery, the crown graft must be carried out in April May ; when the subject is in full swing. To succeed in creating this grafting, you must:

  • Select grafts of about 10 cm and with 3 eyes (or buds).
  • Make a 2.5 cm bevel cut at the base of each graft.
  • On the rootstocks, make vertical incisions sufficient to accommodate the scions.
  • Gently insert the graft to allow time for the bark to peel off, while ensuring that the cambium layers of the subject and the graft coincide.
  • All that remains is to tie up and chew.

It may interest you :

  • All about cuttings

Video: Fruit Tree Grafting for Beginners (October 2020).