Assessment of ornamental value of Vinca major 'Variegata' and Arabis caucasica 'Deep Rose' species in different systems of culture.
Vinca major L. is a Mediterranean species, hemicryptophyte, cultivated in Romania as ornamental plan on walls or cliff arrangements. Due to its biologic characteristics it can be easily cultivated on roofs and harmoniously associated with species Arabis caucasica L. for the setup of green roofs. A species native to the mountain areas of Asia and Northern Africa, Arabis caucasica L. (syn. A. albida Stev.) has been introduced and naturalized in almost all of Europe, including Romania, and at the present time it is part of the ornamental assortment of alpine gardens insuring, through their color and flowering abundance the specific décor in the summer period. The paper has the purpose of analyzing the influence of some culture systems on the ornamental potential of Vinca major plants 'Variegata' L. și Arabis caucasica 'Deep Rose' L. For this purpose we have analyzed the influence of the culture location and the used substrate on the plan growing and development abilities. Experiences were based on the installation of roof and field culture, as well as on the use of three culture substrates of different compositions: a1-forest soil; a2-Novobalt peat mixture (43%), coconut fiber (30%), composted bark (23%), alginate (4%); a3-blonde peat (40%), brown peat (30%), sand (10%) and forest soil (20%). Planting the Vinca major 'Variegata' and Arabis caucasica 'Deep Rose' plants in different culture systems and different types of substrates has determined a differential behavior, with better results, for both species, in case of the substrate comprised of: Novobalt (43%), coconut (30%), composted bark (23%), alginate (4%). Taking into consideration the specifics of the Vinca sort, it is highlighted that it had a remarkable evolution which convinced me to recommend it in landscape arrangements made on roofs and terraces.