Mulching consists in the drafting of materials of different nature on the surface of a soil. This technique has several advantages, since it reduces for example the evaporation of water and limits the growth of herbaceous vegetation that would compete with the development of trees in absorbing nutrients from the soil. It also improves soil temperature and prevents erosion by limiting the action of rain. Mulching can be carried out with different materials: among the organic ones we mention, for example, bark and conifer needles, as well as shredded wood and composting residues. The advantage of these materials is that when they decompose they add new nutrients to the soil, increasing their fertility, but on the other hand they will have to be replenished every one or two years. The only warning concerns the thickness of the mulch block which must not be more than 10 cm and in any case avoid being spread against the shaft collar.
Alternatively, inorganic materials can also be used, such as permeable plastic sheets made of geotextile fabric, which at best contain the development of weeds but have a worse appearance, or decorative materials such as pebbles and crushed stone. In some cases, both organic and inorganic mulching are used to combine the advantages of the two systems.