The project envisages a comprehensive revitalisation of the square. The existing surfaces will be replaced with stone paving, which will give the entire area under the treetops a unified look. The trees will be planted in significantly expanded planting areas and underplanted with perennials. Those trees that have been preserved will have their planting spaces mulched with gravel. In total, six trees will be cut down and 19 new ones will be planted. The individual trees will be planted in connected rooting spaces filled with structural soil, which will improve the trees’ resilience. Structural soil has the ability to hold huge amounts of water, thus serving as a reservoir for the trees. In addition, this improved subsoil is able to withstand loading from moving cars. In Ostrčilovo Square, new Norway maples will be planted to replace old ones, and three sweetgum trees will be added. Across the road, a new rowan tree will be planted in a compacted gravel bed. The northern part of the square has been designed as a quieter area with street furniture. The southern part, which is more open, will provide space for cultural activities (a small market, etc.)
A comprehensive renovation of surfaces will take place in Jaromírova Street. Based on an expert tree assessment, a total of 15 trees will have to be removed. However, after the renovation works, 31 new trees will be planted in rooting spaces filled with structural soil. Where the absence of utility lines makes it possible, the rooting spaces will be connected, or extended to reach the nearest existing tree. The trees lining the street, some of which will be replaced, are of the honey locust species.
The regeneration of the dead end of Svatoplukova Street takes into account the main pedestrian routes towards the railway underpass and the need to provide access to the adjacent buildings. The design divides the surfaces into perennial beds, paved pedestrian and service areas, and relaxation zones with compacted gravel surfaces and street furniture. Two new trees of the sweetgum species (Liquidambar styraciflua) are part of the design. Climbing plants are used to visually separate the public space from the fenced-in area of the railway track.
Planting in structural soil
Trees growing in urban environments are generally exposed to unfavourable conditions. These include extremely small rooting spaces, highly compacted soil of poor quality, insufficient infiltration of rainwater and lack of air in the soil.This is why the new trees in Ostrčilovo Sqaure and Jaromírova Street will be planted in structural soil and their rooting spaces will be interconnected.Structural soil consists primarily of coarse fraction gravel, with large fractions (32/63) used for the foundation and smaller fractions (4/8) used as the planting mixture. Small amounts of compost and biochar are added to provide for the necessary nutrients and water supply. After these layers have been compacted, they are covered with geotextile, which serves as a base for the standard layers forming the road surface. Due to its porous character, structural soil provides enough space for tree roots and allows for sufficient aeration of the space.Thanks to the interconnected root system, trees planted in this way provide enough living space for micro-organisms and symbiotic fungi which benefit the trees (a phenomenon called mycorrhiza). Rooting spaces filled with structural soil also have the ability to hold much larger amounts of water. This facilitates the exchange of nutrients, thus significantly improving the trees’ ability to withstand the difficult conditions of the urban environment.
Prague 2 - Nusle
design 2022, implementation 2022–2023
Prague City Hall, Environmental Protection Department
restoration of linear tree plantations and modification of rooting spaces
graphic design of information panel: KULTIVAR studio – Zuzana Brychtová Horecká; arboriculture: David Hora; budget: Vladimír Mrázek