Tree management

The arboreal heritage of the Municipality of Milan consists of over 240 thousand trees. 
60 percent of the trees are distributed in parks and gardens, 29 percent in rows of trees and the remaining 11 percent in schools or green areas belonging to municipal buildings.
The most widespread botanical species in the municipal area are:

  • maples (Acer);
  • plane trees (Platanus)
  • lime trees (Tilia), which in total constitute almost half of the tree heritage (47%).

Trees in Milan have to live with a series of constraints that often compromise their growth, in particular:

  • lack of attention in avoiding damage to the roots
  • limited growth spaces to share with man
  • "difficult" growth sites,  often  stressed by underground interventions
  • road traffic and construction sites.

Rainfall is also influenced by very rainy years and seasons and others that are decidedly dry. The trend is towards an arid season with pedological effects, therefore with reduced humus accumulation.

The climate strongly influences the growth and rooting of trees, as well as the development of particular pathologies. The frequencies and distribution of rainfall are important.

Especially in urbanized areas, trees must coexist with the technological systems present underground: an important factor both in the planning phase for the insertion of new trees and in the maintenance phase or interventions concerning the technological systems themselves.

Tree maintenance and care activities consist of:

  • pruning
  • pruning (pruning that eliminates dry or excess tree branches)
  • desuckering (removal of suckers, shoots that develop from the rhizome or trunk of a plant, to avoid vegetative impoverishment)
  • monitoring
  • dejection
  • replanting.

These activities are performed in coordination with:

  • Local Police to intervene on street trees
  • Atm to coordinate all interventions that have interference with tram or trolleybus lines
  • roadworks impacting tree growth sites.

As far as pruning is concerned, today the interventions on trees have changed. In particular, pruning cycles, where necessary, must take into account:

  • genus and species
  • monitoring and claims archive
  • rooting site: road rows, parks, schools, proximity to buildings, public lighting, traffic light systems and electrified lines. 

Regarding the replacement of existing trees (therefore felling and replanting), the main causes that determine this intervention concern plants that are not dry or not growing (66%) or plants that present very serious morphological and structural defects (20%). Further causes are adverse weather conditions, diseases, vandalism, damage caused by road accidents, trees rooted in construction areas and soil chemical problems.

Subjects: 

Updated: 29/11/2022