Our cordon apples and pears are pruned largely during late summer. However, there is usually some work to do in winter, cutting back secondary growth and thinning spur systems. The latter is not easy to do until after leaf fall, when the structure is more readily observed. With spring around the corner, it was definitely time to check them over.
Summer pruning is used on restricted forms, because it controls vegetative growth and encourages the development of fruit buds. Usually, only one round of summer pruning is needed, although if there is a great deal of secondary growth, which will vary from season to season as well being influenced by when the pruning is carried out, one might wish to prune a second time. Otherwise, one is left with a certain amount of growth to remove during the winter. This is a simple matter of identifying the thin, young wood, and pruning back to, as a general rule of thumb, one bud above the basal cluster. I am not too strict with this rule, sometimes leaving a little more wood, depending on how it is placed. Any suckers, that is, growth from the rootstock, are removed.
The secondary growth, especially the shorter lengths, is often terminated in a fruit bud. These buds tend to be fatter and more rounded than shoot buds, and are generally fairly easy to differentiate. If the growth is around six inches or less, one might wish to retain the shoot. The decision will be influenced by how well placed that shoot is; in crowded spur systems one might prune it hard back to one bud, whilst in less populated areas, the shoot may be retained. One should not, though, be unduly influenced by the fact that there are one or two apples or pears at stake; pruning is about the long term shape and productivity of the tree, so I can be quite ruthless – if I would not otherwise be happy to have the growth there, it is removed, regardless of any fruit buds. When debating whether to retain a shoot, the strength of the shoot in question should also be considered; if it is thin and weedy, this growth may not bear the crop anyway, so is best cut back.
Aside from the secondary growth, winter pruning gives an opportunity to thin overcrowded spur systems. As the trees develop, this will become a more important part of the job, but at the moment they are not old enough for there to be that much overcrowding. A little thinning was done here and there, but one pear in particular had developed a somewhat messy system of spurs that needed attention. The idea is to remove stems that are too close together to allow the fruit to develop properly, and to prune out some of the older fruiting wood. The latter will not be a problem for some years so at the moment it is more about preventing wood from crossing and interfering, and allowing enough space for the fruit and to promote good air flow. Unlike the secondary growth, where one can be entirely ruthless, these spur systems have taken years to build up and are critical to the crop, now and in the future, so some care is needed to remove only that which really is surplus to requirements.
Along with any pruning needed, winter is a good time to check the ties. At the moment, the main stem of each cordon is tied to a cane, which is strapped, with cable ties, to horizontal wires. The cane is used, not only to help train a reasonably straight stem, but also to avoid rubbing between the wires and the stems. I am thinking, however, that next winter the canes could be removed as they are not doing much anymore and loose cloth ties could be used to secure the now maturing stems directly to the wires, tying in such a way as to put material between the stem and the wire. For this year, though, the canes were retained, but the ties were cut and new ones put in place to allow room for the stems to expand further. The canes appear to be getting a little brittle now, and one had to be replaced, breaking under the weight of last season’s crop.
It has also been a couple of years since we treated the soil. The soil was well prepared, with lots of organic matter and a sprinkling of bone meal. We then applied a thick mulch of bark chippings, much of which has now decomposed. There are certainly no signs of any deficiencies, but it was, perhaps, time to put something more into the soil. First, weeds were removed; these were not hard to take away, as the mulch had left the top layer of soil nice and loose. Then a dressing of fish, blood, and bone was applied, followed by a thick mulch of organic matter, comprising manure and composted bracken. It is important to make sure that any mulch is kept clear of the trunks, to help avoid rots developing. This treatment should keep the trees well fed for another year or two.