The materials used for the preparation of green roof substrate
include exfoliated vermiculite, expanded perlite, crushed
brick, sand and coco-peat (29% moisture content). These materials
were obtained locally and used in their original form in
experiments. The physical and chemical characteristics of
these substrate components are listed in Table 1.
P. grandiflora was chosen as test plant species for the present
study. The plant species in the form of cuttings were
purchased from a commercial nursery. P. grandiflora possess
several advantages which are essential for green roof plants
such as ability to thrive in extreme dry and water scarcity
conditions, have short and soft roots (DDC, 2007), and provide
excellent ground cover.