Principles Of Pruning

Press, Volume CVI, Issue 31088, 17 June 1966, Page 6

Principles Of Pruning

At this time of the year one of the major preoccupations in the garden is that of pruning, whether ornamental or fruit bearing. It is the one task which is most often regarded with suspicion by some and perhaps with much trepidation by others.

The Pocket Oxford Dictionary defines the word as getting “rid of dead or overgrown parts” which may be sufficient explanation to the uninitiated. It is more precisely a skill, or perhaps an art or science if you prefer, of using surgery to influence a maximum of balanced growth and flowering in a botanical subject and at the same time maintain an ideal shape. This could also be

described as the major objective of pruning. Although concern here is primarily with fruiting subjects, many of the detailed objectives and principles could be applied to ornamental, too. Initially, pruning is required to build up a tree strong enough to bear without breaking limbs, good crops of quality fruit of adequate size. For instance, leaders should not all arise from close positions on the trunk as this would lead eventually to a weak crotch. Shaping is important to admit adequate sunlight to all parts and to facilitate picking and so pn. Sunlight is a vital factor to the plant’s metabolism and it is necessary to ripen fruit. Badly placed branches can cause mechanical damage. Young Wood Pruning ensures an ample supply of healthy young wood to replace spent and diseased portions. If a tree is left to grow as it pleases, unless growing under exceptional circumstances, old wood may eventually become confined to the extremities. Loss of vigour results. Tied up with the foregoing factor is the need to keep a balance between wood gowth and flower or fruit bud production. In this respect it is necessary to know the fruiting habits of the individual kinds of varieties of trees, vines, or bushes, concerned. Finally, regular pruning enables us to remove dead,

diseased or broken growth, thus avoiding or reducing the carry-over or spread of diseases such as powdery mildew, fireblight, coral spot, silver leaf. It is now possible to consider some principles of pruning which are adaptable to most plants. Hard cutting produces strong growth under normal circumstances of adequate growing conditions. It is therefore possible to stimulate a weak grower into pronounced vigour simply by some severe but skilful surgery. Horizontal growths are more conducive to flower bud production and do not tend to grow so strongly. More upright and vertical growths tend to grow more strongly and are less inclined to develop flower buds. Constant division of a limb, induced by continually cutting back succeeding growth arising from one place, progressively weakens the resultant growth. The flow of sap from the roots rises to the highest point. In consequence that point, usually the leader, will receive the greatest flow of sap and will grow more vigorously at the expense of the others. This, of course, indicates that leading shoots should be kept at a reasonable level to each other, but it also enables us to strengthen weak growth by leaving it longer than surrounding stronger ones, which is especially helpful during the early formative years.