Spring is stirring and it’s time to get grafting. More particularly, to get on with grafting apple trees.
Grafting has been going on for thousands of years. Possibly originating in China, it was certainly commonplace in ancient Greece and the Roman Empire.
Simply put, grafting involves splicing a rootstock and a scion (or shoot) together. Provided it is done correctly, the cambium (the actively growing part) of the rootstock and the scion will readily fuse together and produce new phloem and xylem (the tubes that transport food and water in a plant) that run smoothly between rootstock and scion.
The scion wood comes from the tree that you wish to grow – e.g. a particular variety of apple.
Rootstocks are chosen for the characteristics that they will confer on the scion wood. The main focus is on the size of tree the rootstock will produce, but much work is also done to develop rootstocks that confer some degree of disease or pest resistance through to the scion wood. The rootstock also has a strong effect on the longevity of the tree: in general, rootstocks that produce a dwarf tree (e.g. M27) will be shorter lived than full-sized standard trees. Most rootstocks used commercially for apples in the UK are known by an M number – e.g. M27. The M refers to the East Malling Research Station where the rootstocks were originally bred and developed.
Why bother? As mentioned, grafting to a rootstock gives you control over the size and some elements of disease and pest resistance. Moreover, it ensures that your crop tree will come true. If you plant an apple pip, you’ll never really know what tree will result – it’s likely to be a hybrid (due to pollination) and is also, quite probably, going to produce inferior fruit. Finally, grafting speeds up the propagation process. In a couple of minutes you’ll have a small tree. If you planted a pip, you’d wait two or three years to get a sapling of the same size.
Why not just root cuttings? Well, you can do this. However, by doing so, you won’t be gaining the benefits that a specially bred rootstock could bring (control of vigour, disease resistance, etc.). What’s more, many of the tastiest apples either do not have a very good natural root system themselves, or they have such a prolific root system that within a few years your tree will have grown so vigorously you won’t be able to reach the fruit anyway!
Although February and March are the main times for grafting with scions, you also get a second chance for propagation during the summer when “budding” or bud grafting can be used. For this, rather than using a stem from the parent tree, only a bud is needed. This method is particularly popular with commercial propagators because they can bulk up their material very rapidly; just think how many buds are on one branch. It’s also a useful way to save the genetics of old trees that may have become too gnarled and unproductive to take a viable scion from.
There is a wealth of information on all types of grafting on the internet. Here in Wales, Paul Davis of Dolau Hirion Nurseries is one of the leading experts on all things apple and has some great information on his website. If you don’t feel confident to graft your own trees, Paul offers a grafting service.