It’s time to size up your winter pruning
LAST spring, summer, autumn and now winter have each been remarkable, though for different reasons. Spring was historically cold; summer brought drought; then autumn was a sunny parade, and now winter, after a damp start, has been incredibly mild, to the extent that plants are well ahead or just befuddled.
Nasturtiums still in flower, and lupins reported too, wallflowers opening, lobster-claw in flower in December, hazel catkins shedding pollen before the turn of the year — strange, to say the least. But nature has a way of levelling things out, known as dynamic equilibrium, in which the components of a system act to balance each other. If one part becomes excessive, the related parts move to restore equilibrium. Dynamic means the system moves.
Plants also act in response to changes in their system’s equilibrium but they always take advantage of improved circumstances and make any necessary adjustment for later, and we might as well do the same as plants, or at least continue the tried and trusted that has stood for time.
Winter is the usual time recommended for the annual pruning of apple and pear trees, and blackcurrant and gooseberry bushes, while dormant. But they can be pruned well into bud-break in March or even April but it is convenient to have it done before other aspects of the garden demand time. Plum and cherry trees are pruned in summer to avoid diseases.
Pruning is done for several reasons: to keep the trees or bushes to a manageable size, to improve fruit quality and to reduce disease. If it is not done annually, the trees get too big and more drastic work has to be done eventually.
The principle of apple tree pruning is to maintain a renewal supply of vigorous young branches, because it is on this wood that the best fruit is carried. Pruning reduces the amount of fruit carried but directs the efforts of the trees into the smaller numbers, resulting in larger fruit of better quality and flavour.
The aim is to prune out the number of shoots by a third or a half, and shorten the remainder by one-third or half. Pears are pruned in the same way, except that they form fruit spurs to a greater degree, but some new wood will always be required for replacement.
Blackcurrant bushes can have about one third of the shoots, the older ones, removed. Redcurrants and gooseberries have fruiting spurs, some can be thinned out and the young growth is shortened back to a few centimetres.
These rules-of-thumb are good for trees and that are pruned each winter but pruning is often forgotten for years and the trees grow too big and difficult to pick and to prune. When this occurs, more severe pruning is necessary.
First, all dead, broken or diseased branches are removed. Then crossing branches have one or both removed and also branches growing towards the tree centre. The remaining branches are shortened by one-third or a half of their length, and reduce by half the secondary branches both by number and length.
An apple tree also follows the rules of dynamic equilibrium and, when pruned hard, tries to replace the lost ones with a burst of growth, because trees want to grow bigger. The new soft growth is called ‘‘water shoots’’, and they should be removed in early summer when finger-length, forcing growth into fruiting branches.