###### Abstract  
The negative effects of urbanization such as urban overheating, pollution, high population density and so on are being experienced by city inhabitants more than ever, thus motivating a high number of researchers to find viable solutions to mitigate these effects. The present paper aims to identify an assortment of ornamental plants appropriate to be successfully used in various facade covering systems for buildings located in Eastern European countries. For this purpose, throughout a vegetation season, the project's team thoroughly monitored the percentage of survival, the coverage degree, and the behavior (biometric aspects and visual quality) of ten flowering species planted vertically and being oriented towards all four cardinal points. At the same time, the team conducted a thorough monitoring of some parameters of the soil (pH, humidity, and temperature) and of the outside environment (light intensity and temperature). Two experimental structures were built, insulated on the inside and covered at the top with thermal insulating panels, to simulate the same conditions of an insulated and unheated construction. The monitoring results showed that _Heuchera x hybrida_ 'Fire Alarm', _Heuchera x hybrida_ 'Marmalade' and _Festuca glauc_ had a healthy appearance throughout the year, regardless of the cardinal orientation while providing a good coverage of the vertical surface. great facades; ornamental plants; urban environment; green building envelopes; vertical greening system +
Footnote †: journal: Applied Sciences  
10 October 2021 30 December 2021 30 December 2021 34 January 2022 30 December 2021 30 December  
is the vertical development of gardens. Currently, the installation of green roofs and walls are two techniques serving both to improve habitats and possessing great potential to achieve reconciliation ecology in urban areas [2]. Over the past decades, several studies have been carried out that have successfully proven that green walls can improve the performance of buildings by contributing to the consolidation and restoration of the urban environment [3]. Plants act as a solar filter that reduces heat on the facade of a building, thus preventing the absorption of thermal radiation by the construction materials [4]. The vertical arrangement creates an external insulating layer that can improve the thermal insulation coefficient of the building, contributing to energy saving in the summer by reducing the need for air conditioning and by reducing heat loss in the winter [5]. The microclimate created at the facade level is characterized by slightly lower temperatures and a higher relative humidity, which means that the green screen acts as a wind barrier and confirms the evapotranspiration effect of the plants [6]. Plants and partially the substrate that is part of a green facade system possess a number of beneficial functions, such as increasing biodiversity and ecological value, mitigating the urban heat island effect, providing thermal and sound insulation, increasing indoor and outdoor comfort, and improving air quality and social and psychological well-being of city dwellers [7] which further leads to their better health [8]. The use of plants to mitigate the heat island effect of urbanized areas and improve the quality of the environment becomes a key design aspect in the development of modern buildings. Moreover, the widespread use of green facade systems could also present a real impact on transforming the urban landscape [9]. Plants used in green facade systems must be able to cope with extreme conditions such as severe temperature differences, high pollution, and possible lack of water [10]. This is why it is absolutely necessary that the plants proposed to be planted in these systems are tested in advance in the climatic conditions of the area where they are to be used. [PERSON] [11] and [PERSON] [12] pointed out through their studies that psychological health is affected by living and working in cities due to stressful work environments.