In the Brera Botanical Garden the many trees give it a special characteristic charm in every season. They clearly dominate the Arboretum, but they also figure in the two formal sectors, even inside the flower beds, witnesses to the place’s long history.
Many of them have exotic origins and have been collected over time because of their scientific and ornamental interest; some are very old and very large. Among them, the two centuries-old Ginkgo biloba, a male and a female, the oldest trees in the Botanical Garden, dating back to the period of its foundation; the silver linden (Tilia tomentosa) whose grandeur catches your eye the moment you walk through the entrance; there’s a majestic Caucasian wingnut (Pterocarya fraxinifolia) characterized by a massive trunk crossed by deep folds and branches, spreading out horixontally and creating a thick green dome. In the farthest corner of the Arboretum a large yew (Taxus baccata) shades the underlying stone bench. This is a female specimen, possessing the typical seeds covered by a fleshy red casing. The Garden has other examples of this species, but this is the most significant since it boasts well developed wide branches.
Another plant, that at first sight is very similar to the yew, is part of the Gardens’s arboreal heritage: this is a male specimen of Torreya taxifolia, a highly endangered species in Florida, its native habitat.
Besides the yew and the torreya, there are other conifers in the collection: Cryptomeria japonica, Cupressus torulosa (Himalayan cypress) and a Japanese larch (Larix kaempferi). The latter is certainly a rarity, seeing Milan’s climate and altitude. It is the only one in the group that loses its leaves in autumn, as is typical of the larch.
The stumps of several dead trees have been left in place as witnesses to life in the past. From one of them a sucker developed, regenerating the mother plant, an Osage orange (Maclura pomifera). Other parts of the trunk are useful for observing the annual growth rings and the tree’s decomposition.
In the central area of the Garden, there’s a Firmiana simplex in a flowerbed. Its large leaves give a lot of shade, which explains its common name of “Chinese parasol”. It also has a very particular green and striped bark and leaf scars, similar to eyes, arranged in a helix running down the entire trunk.
A young holm oak (Quercus ilex), the Mediterranean tree par excellence, is part of a small collection of oaks: for example Quercus castaneifolia is about 80 years old, while the vallonea oak (Quercus ithaburensis subsp. macrolepis) is still very young.
Each tree in the Botanical Garden has its own particular story to tell. In the last 30 years many have replaced the previous ones, new ones have been planted and others that were young are now majestic.
Firmiana simplex
bark with a leaf scar
The trees are cared for by carrying out periodic monitoring of their health, thanks to non-invasive investigations to evaluate their physiological and phyto-pathological condition and stability, using modern arboriculture techniques which the Brera Botanical Garden has applied since the 1990s.
In particular, the VTA (Visual Tree Assessment) is adopted, a methodology through which the tree is visually analyzed to identify any external symptoms that may be a sign of mechanical or physical defects inside the tree. In case of external symptoms, a more in-depth instrumental investigation is carried out.
The trees are also investigated and maintained by tree-climbing, a technique that safeguards their physiology. This is performed by specialized arborists using methods and materials similar to those of mountaineers. These allow the climber to attend to the apical parts of the trees with safety since the trees in the Garden can sometimes reach 40-50 meters. This technique is well suited to the fragility of a historic place like the Botanical Garden of Brera, where you aren’t allowed to use machinery or cranes.