The Greenrooftops mixed sedum mat comprises of a recycled polyester fibre mat, with a thin layer of specialist green roof substrate which the sedum plants themselves grow. Sedum blanket is grown from sedum cuttings, so will have less varieties compare to sedum modules which are grown from seed. Different varieties have a range of different flowering periods resulting in constantly changing colours throughout the summer and early autumn. Sedum blanket full system build up: underlay layer, water reservoir layer, 2-3cm substrate, sedum blanket.