Extensive Green Roofs, are commonly characterized as Roofs planted with low maintenance plants
A extensive Green Roof - is characterized by its vegetation
, ranging from sedum to small grasses, herbs and flowering herbaceous plants, which need little maintenance and no permanent irrigation system. The growing medium
depth for an extensive green roof system is typically 6 inches or less.
These systems are ideal for efficient storm water management with low maintenance needs. Extensive green roofs are very cost efficient and can easily be combined with Solar PV systems.
Light weight Green Roofs are often created by minimizing the depth of growing medium
Although some suppliers might offer systems that can develop in only 2 inches of growing medium, we HIGHLY recommend deeper layers of growing medium for a lush and diverse plant development. In the case of a mono culture, conditions are so extreme in a thin medium layer, that only one or 2 Sedum plant varieties survive.
A educational article has been written on what influence the thickness of the growing media has on plant development, you may find this here: (CLICK)