Recently, the design of new substrates capable of sustain an adequate plant
development in Green Roof systems under Mediterranean climatic conditions is a
challenge due to the unfavorable hot and dry conditions. The use of suitable lightweight
substrates which can promote an adequate plant growth and maintenance
over time is an important achievement as well as the plant species selection. The most
commonly used plants in Green Roof systems are the Crassulacean since they are
perfectly fitted to drought conditions. In this sense, the use of herbaceous and shrub
endemic Mediterranean species could provide an added value in green roof designing
under semi‐arid conditions. Therefore, we aim to evaluate the growth of two endemic
species (Silene vulgaris (Moench) Garcke and Lagurus ovatus L.) in two different
substrate types with two different depths. To be precise, one substrate was made of
a mixture of compost and crushed bricks (CB) (1:4; v:v), and the other one was made
of compost‐soil‐bricks (CSB) (1:1:3; v:v:v). Physichochemical, biochemical as well as
microbiological properties were evaluated in both substrates in order to study its
suitability as plant growth basis. The results showed that both substrates showed
adequate physichochemical properties to promote plant growth, but the CSB mixture
presented better biochemical and microbiological properties than CB, allowing a
suitable environment for microbial and plant development. Furthermore, both plant
species had higher coverage and grater SPAD values in CSB than in CB mixture, and
this growing was higher above deeper substrates (10 cm) than on 5 cm‐substrate
depth, being this parameter more significant for plant development than substrate
composition.The authors thank the INNPACTO project (IPT‐
2011‐1017‐310000) by funding from the
relevant trial