Pruning is one of the most critical gardening tasks, determining whether the garden plants will develop satisfactorily or not. Carried out correctly and at the right time, the trees grow in the desired manner, the bushes look lush, green and healthy, and the flowering plants brighten up the garden with color. Performed at the wrong time, serious, long-term damage can be inflicted on the trees, the shrubs and bushes are liable to develop an open, "leggy" habit and many herb plants and sub-shrubs, while green on top, become bald and unattractive below. In a nutshell, when it comes to pruning, timing is crucial.

Deciduous trees and landscape shrubs

The one group of plants that should not be pruned in the spring is plants that naturally drop their leaves during the winter. In the dormant season, carbohydrates and mineral nutrients dissolved in sap are stored in the plant's tissues. At the onset of spring, the sap rises in the plant and is carried to all its growing points. Pruning cuts carried out at the time when this process is occurring, causes the sap to "bleed" out of the plant, thus causing it to lose vital energy sources. Arboriculturists today, believe that maintaining a positive energy level in a tree, is the single most crucial factor for its long-term health and survival. Deciduous plants should of course, have been pruned in the winter.

Evergreen trees and shrubs

This is precisely the best time of year to prune evergreens and plants sensitive to cold, which should not have been touched during the winter. As the spring, especially in Mediterranean and hot, dry, summer climates, is the principle growing season for most garden plants, it is best to direct the new growth just as it is beginning. Conversely, pruning tissue a month or two after it has sprouted means that the tree or shrub has expended vital energy, for no purpose.

Flowering Shrubs

Despite the above, care must be taken when it comes to flowering shrubs. Amongst deciduous species, one has to know whether the flower buds develop on the current year's spring growth, or on that of the previous year. Not a few home gardeners are disappointed with their lilac bushes for instance, which "never seem to flower", the reason being that they dutifully prune the shrubs in the winter, thereby removing the flower buds in the process! Such plants, which include some shrub and species roses, should be lightly pruned after the flowers have withered.

Flowering evergreen shrubs rarely if ever belong to this category, and so for the most part should be pruned in the spring. Pruning shrubs is largely a matter of removing old and dead growth, and shortening branches by between a third and a half, in order to encourage dense and compact growth.

Tree pruning on the other hand is all about careful shaping so that the growth pattern appears as natural as possible. This should apply in my opinion as much to fruit trees as to ornamentals in a private garden. While farmers cut back branches in order to extract more fruit from the tree, and also to make the picking more economically efficient, the tree in a garden has amongst other purposes, a vital aesthetic role to play and should be treated as such. Its long term health should never be forgotten either.