©2006 Ayako Nagase
Environment of green roofs is harsh for plants because of drought, limited water availability, wide temperature fluctuations, and high exposure to wind and solar radiation. Selecting plants capable of surviving under these conditions is a critical step in successful green roof implementation. We used semi-extensive green roofs to extend the selection for plant selection. Semi-extensive green roofs use light weight substrates similar to extensive green roofs but they have slightly deeper layer of growing medium (10-20 cm) and therefore enable a more diverse range of plants to be grown (Dunnett and Kingsbury, 2008). We tested several species of annual meadows and geophytes for extensive green roofs in the UK.