Based on the requirements of extensive green roofs, ploylactide (PLA) fibers, cotton fibers, polyester (PET), and low-melting-point LMPET fibers are combined and produced culture mediums for Crassulaceae plants. The resulting mediums are tested for their physical properties and found to be light weight, which is a required condition for plant growth. These features contribute to efficient construction and maintenance. In addition, the optimal cooling effect of the culture mediums is 9.6 A degrees C, which significantly reduces the amount of heat that invades indoor spaces. The decrease in the amount of heat indoors results in a lower demand for air conditioning so as to achieve energy conservation. The results derived from this study help in the promotion of green roofs, thereby slowing down the urban heat island effect and global warming.