The Rooted in Research™ Tough Stuff mix is designed with species of Sedum that exhibit the greatest hardiness and rugged survivability on a green roof.  These plant species were selected based on a scientific research study which showed them to be the most robust of Sedum species and able to survive on the most extreme of green roof environments.   The Tough Stuff plant mix is low maintenance, drought tolerant, extremely durable and can resist extreme heat and cold.  This plant mix works well for harsh climates such as tall buildings, direct sun, or in cold climate regions.