Acclimatization of Mediterranean Native Sages (Salvia spp.) and Interspecific Hybrids in an Urban Green Roof under Regular and Reduced Irrigation

Abstract

Native-to-Greece sage species, namely, Salvia fruticosa, S. officinalis, S. pomifera ssp. pomifera, S. ringens, S. tomentosa and interspecific hybrids, were evaluated for their acclimatization in an extensive Mediterranean green roof during summer under regular and reduced irrigation (every 2–3 days with substrate moisture 16–22% v/v and 4–5 days with substrate moisture 7–11% v/v, respectively). A substrate (grape-marc compost:perlite:pumice, 3:3:4, v/v) that was 10 cm deep was used. Regardless of the irrigation frequency, S. pomifera ssp. pomifera × S. ringens and S. officinalis × S. pomifera ssp. pomifera showed the highest survival of all hybrids and species, along with satisfactory growth, while S. fruticosa showed the lowest survival. Reduced irrigation resulted in the reduction of aboveground and root biomass, with no damage to the photosynthetic apparatus. S. fruticosa showed the highest (53%) aboveground biomass reduction and S. officinalis, S. officinalis × S. ringens and S. pomifera ssp. pomifera × S. ringens showed the lowest (28, 23 and 3%, respectively), while S. officinalis × S. pomifera ssp. pomifera and S. pomifera ssp. pomifera × S. ringens showed the lowest reduction in root biomass (13 and 16%, respectively). With a reservation for S. fruticosa, Greek Salvia spp. and their interspecific hybrids studied in the present work are recommended for sustainable exploitation in extensive green roofs in arid regions and generally in xeriscaping.

Growing of the Cretan Therapeutic Herb Origanum Dictamnus in The Urban Fabric: The Effect of Substrate and Cultivation Site on Plant Growth and Potential Toxic Element Accumulation

“…Taking into consideration that although foliar and root growth was greater in the soil substrate, the general plant growth was also satisfactory, and flowering remained unaffected in the soilless one; therefore, the soilless substrate could be recommended for green roof cultivation in order to achieve reduced construction weight. This is in accordance with other studies on O. dictamnus [ 10 , 43 , 49 ] or other Mediterranean xerophytes [ 21 , 22 , 50 , 51 ], in which lightweight and highly porous soilless substrates were recommended for green roof cultivation.…”

“…Cultivation in urban green roofs of perennial plants with dual character, i.e., with ornamental and commercial value, such as O. dictamnus , is an interesting combination of green roof technology for environmental benefits with urban agriculture [ 21 , 22 ]. Furthermore, in semi-arid regions with limited water availability for urban green use and in view of the climate crisis, which is expected to exacerbate drought and heat conditions on green roofs, the need to explore the possibility of using native species including herbs with limited water needs and with tradition of use by the local community, is particularly attractive in the context of sustainability of the city [ 21 , 22 , 23 , 24 ].…”

Investigation of the Effects of the Explant Type and Different Plant Growth Regulators on Micropropagation of Five Mediterranean Salvia spp. Native to Greece

“…Therefore, Salvia spp. native to eastern Mediterranean regions are worth promoting for use in these landscape regeneration contexts, due to their resistance to xerothermic conditions, low maintenance needs, and their contribution to the rescue of insect pollinators [14][15][16][17][18]. In addition, the floriculture industry is constantly looking for new plant species to compete in international markets, and the Mediterranean flora is an inexhaustible reservoir.…”

“…In Greece are found 30 taxa (species and subspecies) of the genus Salvia [19]. Two of these are widely known commercially as medicinal and ornamental plants, S. officinalis and S. fruticosa (S. triloba), and there are hundreds of research papers on their properties [9,[15][16][17][20][21][22][23][24]. However, a number of the other native sages of Greece have also been studied for their medicinal, cosmetic, and floricultural value [16,17,23,[25][26][27][28][29][30][31][32][33].…”

“…All the above sages have been found to be suitable for use as ornamental plants under limited water supply [14][15][16][17], which makes them valuable plants for xeriscaping and landscaping in arid and semi-arid regions. Research on their propagation using stem cuttings has shown that this is a suitable method for their commercial production [37], although its effectiveness may depend on the season or climatic conditions.…”