And he will

Pruning, a fundamental task for obtaining quality timber.

Achieving quality timber depends on many factors that begin when we choose the planting site, the species, the seedling, the planting method… but, fundamentally, on carrying out an appropriate pruning programme. Pruning at the right moment, in the right season, with the proper tool and with well-made cuts is essential to produce good timber of any species.

The following video tutorials summarising pruning techniques for conifers and broadleaf trees can be consulted:

Video tutorial on pruning conifers in Galician and in Spanish

Video tutorial on pruning broadleaf trees in Galician and in Spanish

Video tutorial on pruning chestnut trees for fruit in Galician and in Spanish

Pruning seasons

Until a few years ago, winter was accepted as the appropriate and widespread time for pruning. In recent years, research has shown that this period was not always the best; in fact, for almost all forest species a different season is far more suitable. Pruning in winter, and in a damp season in general, carries the risk that the cuts remain open until spring, when the rise in sap begins to close them, exposing the tree for a long time to all kinds of pathogens entering through the wound. This is the main reason why it is recommended to postpone pruning until more benign seasons.

Recommended pruning times

Species	Pruning season
Birch (Birch specimen	Between May and August
American oak (Red oak)	Late winter, just before it sprouts, or in July and August
Native oak (English oak)	Between July and August
Chestnut tree (Chestnut specimen	When it begins to sprout, between 15 March and 15 April
Cherry tree (Prunus specimen	Between June and July
Poplar (Poplar specimen	Winter, and a review of thieves in summer
Eucalyptus (Eucalyptus specimen	Preferably in spring
Ash (Ash tree specimen	Between June and August
Walnut (Walnuts specimen	Mid-June to mid-July, in the spring before they sprout, or even in August or September.
Oregon pine (Pseudotsuga menziesii)	Summer
Pine of the country (Pine maritime)	With dry weather in the hot months
Significant Pine (Radiata pine)	With dry weather in the hot months
Cherry tree (Acer specimen	Winter, spring or summer
Sequoia (Sequoia specimen	Summer

How to prune

Throughout the production cycle of a species, two types of pruning must be carried out: the Formative pruning in the first 10 years and the Quality pruning, which can end at 20 years in some species.

The objectives of formative pruning are:

• To achieve a unique and vertical guide.
• Prune the thickest and most vigorous branches.
• In the case of broadleaf trees, prune any poorly formed or damaged plants. There is no need to fear pruning; when carried out at the right time and in the right place, it is the best solution for replacing a crooked, misshapen plant with a straight, knot-free trunk.

The objectives of quality pruning are:

• Obtain three or six metres of knot-free log.
• Prune branches up to 3 cm thick.

To do this, you must always:

• Clean cuts alongside the shaft.
• Use appropriate tools.
• Disinfect tools in cases of maximum risk and value to the plantation.

Pruning is as necessary as not pruning too much. As a general rule, it is recommended that you prune to one third of the tree's height. Excessive pruning slows the tree's growth (by leaving it with too few leaves it has more difficulty feeding) and in some species causes epicormic shoots to appear on the pruned part of the trunk.

One of the keys to good pruning is to do it at the right time, on branches less than 3 centimetres in diameter. Pruning branches over 5 cm in diameter at the trunk insertion makes little sense, since the damage already done to the wood cannot be remedied, so all you achieve is spending money and effort for no positive result.