In our polytunnel we have a small peach tree, a Pêche de Vigne, which I planted in a very large container sunk into the main bed to keep the roots from spreading into the other growing areas. The tree will, if the hand pollination was successful, bear for the first time this year. Last year there was a little blossom but the tree was too young to carry any fruit and in any event it would have been unwise to let it try, as it is better in the long run to give it time to establish properly before bearing. This year, it has carried a great deal of blossom and I have pondered the dilemma of how best to contain its growth within the confines of the polytunnel.
Peaches, in common, oddly enough, with sour cherries such as the Morello, but not sweet cherries or apricots, are among the more labour intensive fruits to cultivate, especially in restricted forms, as they bear only on last year’s wood. Pruning and training is therefore focussed on providing a source of new fruiting wood each year whilst removing the old, now useless growth. A different approach is needed when dealing with restricted forms than with a full size tree. One cannot allow it to expand uncontrolled as it will very soon fill the available space with unproductive old wood, nor can one start arbitrarily cutting back the growth as this will remove the fruiting wood.
Fan trained peaches are relatively straight forward to deal with. They are labour intensive, but the approach to take is usually fairly obvious. Our fan trained trees are a week or two behind the Pêche de Vigne and I will follow up with another article when we deal with them. For the small peach bush, however, the choices are not so simple, and I have spent some time recently wondering how best to deal with it.
For restricted forms – that is, anything other than a standard or half standard – it is usual to establish a number of framework branches from which fruit bearing wood will be developed. A length of fruiting wood will, hopefully, provide replacement shoots from nodes near the base that can be trained in whilst the fruit develops on last year’s growth. After fruiting, the old wood is pruned out, leaving the new wood in its place. To train a modest bush form, one can select four or so main branches forming an open centred goblet shape that provides for plenty of air and light in the centre of the bush. From these scaffold branches fruiting laterals are allowed to develop to bear the crop.
When I planted the tree in the polytunnel, I knew that I would have to come up with an appropriate way of dealing with the vegetative growth to keep it from taking over, but blissfully ignored the issue whilst it was not a problem. Looking at the bush now, it has a main leader, which, following an ill advised cut by the supplier, kinks to one side with the subsequent year’s growth. From the leader a large number of nicely placed laterals have emerged to form a fairly pleasant bush; a little scrappy perhaps, but not too bad. However, when looking for four or so scaffold branches it was not at all clear which to choose. Although I have not seen it recommended for a peach bush, I decided to grow this with a central leader and attempt replacement pruning of all of the side shoots. This is, in one respect, an easy way out, as, if successful, the shape of the tree should be much same next year, so I can always change my mind later and adopt a different approach. Time will tell whether it was a good decision.
The first part of the yearly pruning and training regime is undertaken as the blossom falls and the first shoots emerge. When the shoots are, say, two inches long, those that are not needed are pinched out or rubbed off. If this is not done, the tree will very quickly become overburdened with vegetation, not to mention wasting energy growing useless wood. For each lateral, a couple of potential replacement shoots were identified near the base. I generally favoured outward facing buds, and otherwise those that would not result in overcrowding other growth. Two shoots are ideally retained. Later in the year one may be removed, or perhaps both retained if suitable, but it is sensible to keep a spare shoot in case one is damaged or otherwise fails later. The terminal shoot, that at the end of the lateral, is also retained to carry the sap, but the growing tip can be pinched out later in the year after half a dozen leaves have developed. All other shoots are removed. This must be done carefully as many shoots will be adjacent to the blossom and one can easily damage the blossom when pinching out the shoots.
The result can be a little bare looking, but removal of these excess shoots at this stage is important to get the tree growing in the right way and prevent the vegetative growth from taking over and shading the developing fruit. One is always at the mercy of the tree as to where the shoots appear and it is a case of making the best of what is available. I quickly found that being a perfectionist when it comes to pruning and training is just not possible. A perfect fan exists only in a drawing. Depending on how well this form of pruning works for this small central leader bush, next year I should still have the option of continuing with this form of training or changing to adopt a number of fixed scaffold branches.