How one should deal with wood prunings—removal to a different place or leaving it in the planting, with or without reducing its size or concentration—depends on the planting’s type, character and atmosphere. In highly refined plantings, one will always remove the waste for aesthetic reasons. The rougher its character, the more wood waste one can leave on the spot. Removing organic material implies reduction of soil fertility. In the long run, the removal of wood waste may therefore exert an impoverishing influence on the vegetation. It will depend largely upon the nutrient situation of the soil and the period over which it takes place. Thus, rich soils will hardly be influenced by the removal of wood waste, as the period over which this takes place (the duration of our intervention) is too short to have any effect. Poor, dry soils, however, may undergo negative effects sooner. If desired or necessary, the wood waste may be brought back later to the spot in the shape of thoroughly composted material, applied with care on a small scale.
Leaving rough pieces of wood waste on the spot is, in most situations, less desirable for a number of practical reasons:
– it is unattractive and for this reason is unacceptable in most cases—this effect is
stronger in small – as opposed to large-scale plantings
– maintenance will be bothersome if there are a lot of dead branches and twigs in the
– visitors may look at it as having an unkempt appearance, inviting illegal waste-dumping
– it may invite wood gathering for domestic fireplaces
– youthful visitors like dragging branches around.
A good alternative is shredding wood waste (the finer the shreds the better), which considerably reduces its volume: 10 m3 wood waste=±1 m3 of shredded wood. Shredded wood waste can, in principle, be brought back into the vegetation from which it originated. It is only a matter of scale. If pruning has been performed with the aforementioned frequency, the quantity of shredded wood produced can be reabsorbed into the woodland planting’s system without adverse effects. If, however, at a much lower pruning frequency, too much shredded material is produced, the surplus will have to be carried off, in order to prevent excessive blanketing of the surface.
When the shredded wood waste is brought back into the vegetation—often by ejecting it straight from the shredder into the planting that has just been pruned—the following points should be noted:
– the wood shreds should be applied in a thin layer (maximum 1-2 cm (0.4-0.8 inches))
and spread evenly over the total surface of the area
– the procedure must only take place during the winter season, i. e. when the vegetation is
dormant—it should never be performed during the growing season! The herbaceous layer will be disturbed (e. g. through suffocation) and the visual aspect will be less attractive.
Another method for leaving wood waste in the vegetation is to concentrate it by creating branch stacks. Branches and thin trunks are stacked lengthwise in stacks that are narrow (40-50 cm (16-20 inches)) and not too high (0.8-1.0 m (2.5-3 feet)), kept together by straight branches stuck upright into the soil. Providing the vegetation’s surface is not too small and the branch stacks are laid out in the aesthetically right places, using more or less curved or winding shapes, this will be a good solution for more extensive, less – refined situations. After each pruning round, the produced wood, after being somewhat shortened, is put on top of the existing stack. The lower, decaying branches in the stack can be pressed together, so as to keep the total height end width of the stack at its original size. If this method is applied with care, the necessity of carrying off wood waste will be eliminated. Branch stacks can provide elements of rest, both as cover for animals and as preventive boundaries against visitors and animals (dogs!) disturbing the vegetation.
Shredded wood from prunings may also be used to improve the soil structure (e. g. of heavy clay soils) or to encourage humus formation, thus creating better opportunities for the application of some naturalistic plantings. Application of an initial layer (15-20 cm (6-8 inches) thick) and yearly supplementary layers of 5-7 cm (2-3 inches) of wood shreds can help create a suitable humus layer.
In large woodland areas one may wish to create working paths especially for the purpose of pruning. Hauling out and shredding the produced wood waste can be performed using these paths, as well as its reintroduction into the vegetation. This may help to greatly decrease the workload. Such paths, when covered with shredded wood as a top layer, may also be made accessible to visitors.