I was chuffed to see today that a couple of the fruit tree grafts I did this spring seem to have taken: both of apple (Malus domestica) ‘Red Devil’. I went on a grafting course with Andrew Lear, a.k.a. Appletreeman, in March, but I was beginning to worry that the skills graft hadn’t taken.
As well as the usual reasons for grafting fruit trees yourself (cheaper trees and the ability to propagate varieties that you like), I am interested in the technique for creating ‘own-root’ fruit trees. Own-root trees are ungrafted trees, that is, ones where the fruiting variety has its own roots rather than a rootstock, so you might wonder what grafting has to do with it. The reason is that fruit trees don’t usually root from cuttings, so you do a ‘nurse graft’, a normal graft with the graft union planted below the ground, using the rootstock as a sort of life support system for the scion until it can finally be coaxed into putting out its own roots.
Own-root techniques are based on the work of Hugh Ermen, formerly of the Brogdale Horticultural Experimental Station. Fruit trees are usually put on a rootstock in order to reduce the size of the tree and encourage fruiting by restricting the amount of nutrients available to it. The downside of the technique is that the resulting trees are less vigorous and more disease prone. Hugh developed techniques for propagation and inducing fruiting which allowed grafting to be dispensed with. His work is now being taken forward by Phil Corbett of Cool Temperate Nursery near Nottingham.
I’m interested in the technique myself because I do a lot of planting of fruit trees in public spaces, some of them quite rough. I think that own-root trees would be tougher and better able to stand up to the treatment they can get in these places. In particular, if they are broken off they come back true, whereas a grafted tree grows back from the rootstock. In the allotment I’m going to have to experiment with own-root techniques simply because my favourite fruit tree, a Japanese plum (Prunus salicina) came from the nursery ungrafted. It’s a vigorous, healthy tree, sure enough, but also going to get too big for its spot eventually. Then I will have to try coppicing it and seeing what the result is. In the meantime I have propagated it by layering branches, another own-root technique, and planted it out round the housing estate where I stay.