Grafting and budding fruit trees

Fruit trees consist of two parts. The part of the tree in the soil is called the rootstock, the part of the tree we can see above the soil is the actual variety of apple, pear, plum, cherry etc. You may well ask, why are trees grown in this way? Why not just plant an apple seed in the ground and grow apples on the tree that develops after the seed has germinated? There are several reasons for this, but the most important factor is that the tree grown from the seed of that specific apple you liked so much will be totally different in taste and appearance. In other words, the propagation of fruit trees of a specific variety can only be achieved by grafting or budding the vegetative part of that variety on to the rootstock.

whip and tongue graft that has taken

Another important reason for grafting the variety onto a rootstock is that this gives us the chance to control the size of the final tree. Considering apples by way of example, rootstocks are produced by means of a careful selection of crab apple trees, according to their tree size and health status. These rootstock are identified by letters and numbers: for example, M27 will produce a very small apple tree, while apple trees grown on type M16 will produce a very vigorous and strongly growing unit resulting in a large tree. The M in the rootstock name comes from Malling, namely the East Malling research station in Kent where a lot of work on dwarfing rootstocks was performed in the 20th century. MM, as in MM106 and MM111, refers to Malling-Merton, and the cooperation between the East Malling research station and the John Innes Institute in Merton.

Let’s consider the origins of a Braeburn apple tree that you have seen in the garden centre. In February, when the tree was fully dormant and without leaves, the fruit tree raiser took a twig from a Braeburn tree, a healthy one-year-old piece of wood of about pencil thickness. He cut a four-bud piece of wood from this sample, using secateurs. This became the scion wood, the graft that he then fitted into a cut on the rootstock. After having tied the graft into position, he then sealed the wound completely with grafting wax. The procedure can be seen in our video demonstrating whip and tongue grafting.

How to graft your own fruit trees

Apple varieties already grafted onto rootstocks and ready to plant during the dormant season are available from nurseries and online. But it is also possible to purchase apple rootstocks, which cost much less than one or two-year-old trees, and graft the variety onto them yourself. In this case, ensure that the rootstocks are certified as virus-free.

Grafting (or whip grafting) is always done during the period of dormancy, in late winter up until the end of March, on a rootstock that has been lifted from the ground, or that has been left in the ground.

In all grafting techniques, whether whip and tongue grafting, rind grafting, or budding, the basic principle is that the rootstock’s cambium cells, situated just underneath the bark, are brought into close contact with the cambium cells of the scion.

In all these techniques, it is best not to touch the cut surfaces of the wood, in order not to interfere with the healing process that forms the callous and determines the success of the graft.

Tools needed for grafting

  1. Grafting tape, available from nurseries and online. This is a fairly thin transparent plastic tape without adhesive. It has a degree of stretch which ensures that the tree isn’t constricted when the trunk grows in the case that you forget to remove the tape. In case of emergency, you could cut a strip from a transparent plastic bag.
  2. Secateurs and a sharp knife for cutting the scion and preparing the graft; lopper (large cutter) to prepare the rootstock
  3. Grafting sealant or wax, available in versions put on cold, or that are melted by warming

grafting tools and materials

How to perform a whip and tongue graft

  1. Locate and cut the scion wood. When cutting the scion wood, ensure that the tree is healthy, and choose one-year-old green wood from the outside of the tree, where there is maximum exposure to the sun. Cut the scion to a length of about 10 cm, with four buds. The bottom bud should be just above the grafting cut, while the top bud will form the shoot giving rise to the central leader. The other two buds may be useful if the top bud fails to develop.
  2. Prepare the rootstock by cutting it back to 15-30 cm above the soil line, with a horizontal cut using the large cutter (lopper).
  3. Prepare the scion with a diagonal cut just below a bud. Cut a “tongue” towards the top of the first cut. This will help keep the scion in position on the rootstock.
  4. Prepare the top of the scion with another diagonal cut above the bud chosen as the origin of the central leader. This bud should be on the side of the scion directly over the rootstock, so that it tends to grow vertically.
  5. On the rootstock, make a shallow diagonal cut upwards, about 3 cm long – a bit longer than the cut at the base of the scion. Then cut a corresponding “tongue” towards the top of this cut on the rootstock.
  6. Push the scion onto the rootstock so that the two “tongues” lock. Ideally there should be a window of exposed cambium on the rootstock all around the scion.
    whip and tongue grafting
  7. Wrap grafting tape around the graft. Tie off by holding a loop open in the tape, winding round once, pulling the end through the loop, and pulling tight.
  8. Apply grafting wax to the exposed cut on the rootstock and the top cut of the scion. This is important because for a few days, the scion will receive no nutrients from the rootstock, and the wax helps prevent it from drying out. Be generous to ensure that the graft is air-tight and water-tight. If a graft fails, it is nearly always due to an opening in the wax covering.
  9. Callousing will appear in about 3-4 weeks from the end of dormancy. The tape can be left on until August, when it can be removed. Cut the knot and unwind the tape, rather than trying to slit open the binding which would risk damaging the bark, leaving a wound which could be an entry for fungi or bacteria.

Watch a video in which William Seabrook demonstrates the whip and tongue graft.

How to rind graft a fruit tree

Rind grafting is similar in principal to whip and tongue grafting, but it is more useful if the location of the graft is a large piece of timber, as in the case of an old tree that you want to graft across to another variety.

  1. If the host tree is a normal rootstock, prepare it by cutting it back to 15-30 cm above the soil line, with a horizontal cut using the large cutter (lopper).
  2. Take the scion, and make a long diagonal cut below a bud, and then take a bit off the end with a more obtuse diagonal cut in the opposite direction. Then make another cut along the side, following the first diagonal cut, but at a 90° angle.
  3. Prepare the top of the scion with another diagonal cut above the bud chosen as the origin of the central leader. This bud should be on the side of the scion directly over the rootstock, so that it tends to grow vertically.
  4. Place the knife onto the bark below the cut surface for about 3 cm, press the blade into the thickness of the bark, and twist to lift the bark away on one side.
  5. Holding the bark away with the knife, insert the scion so that the final right-angle cut along the scion is flush with the bark, and the other cut surface is in contact with the rootstock cambium.
  6. Wrap grafting tape around the graft. Tie off by holding a loop open in the tape, winding round once, pulling the end through the loop, and pulling tight.
  7. Apply grafting wax to the exposed cut on the rootstock and the top cut of the scion. The wax helps prevent the scion from drying out. Be generous with the wax to ensure that the graft is air-tight and water-tight. If a graft fails, it is nearly always due to a crack in the wax covering.

Watch a video in which William Seabrook demonstrates the rind graft.

Bud grafting or chip budding

Budding fruit trees is similar in principle to whip & tongue grafting and rind grafting, except that in the case of bud grafting, an individual bud is inserted underneath the bark of the rootstock. The period is also different: bud grafting is performed in July/August, so that the bud has time to heal into the rootstock tissue.

How to perform a bud graft

  1. Locate and cut the scion wood. When cutting the scion wood, ensure that the tree is healthy, and choose green wood from the outside of the tree, with maximum exposure to the sun. The buds that you need will be midway along the one-year-old wood, which can be identified considering that one-year-old wood is that between the tip of the branch and the ridged band that marks the start of the two-year-old wood.
  2. Remove the leaves from the scion, leaving the leaf stalks. The bud that will be used is located between the leaf stalk and the stem.
  3. On the scion, make a 45° downwards cut about 2 cm below the bud, just a few millimetres deep.
  4. Make another 45° cut about 1 cm above the bud, reaching the same depth.
  5. Then draw the knife down along the stem until you reach the lower cut. Now you can lift the bud out, using the leaf stalk as a handle so as not to touch the cut parts of wood.
  6. Make a corresponding aperture in the rootstock by means of sloping cuts, using the bud section as a size guide. Make the lower cut downwards, and then the upper cut.
  7. Insert the bud section into the aperture in the rootstock. The 45° cut at the base of the bud will hold it firmly in position. Ensure that the cambium layers of bud and rootstock sections correspond. The cambium consists of the xylem and phloem tubes and the growth areas, and it is located just under the bark. There should be a narrow window of exposed cambium visible on the rootstock part.
  8. You can now break off what remains of the leaf stalk.
  9. Starting from the bottom, wind grafting tape tightly around the bud, covering all the cuts and holding the graft firmly in position. Tie off by holding a loop open in the tape, winding round once, pulling the end through the loop, and pulling tight.
  10. Callousing will take place from about 10 days after making the chip bud, and it will be visible through the transparent tape. It is best to leave the grafting tape on until the following spring.
  11. Before bud burst, carefully remove the binding. You will now be able to see whether or not the graft has been successful.
  12. If the graft has taken, cut the rootstock down to just above the graft, sloping the cut away from the bud. Seal this cut with grafting wax or Heal and Seal.

Watch a video in which William Seabrook demonstrates the chip budding technique.