Developed and tested at Cornell University, CU-Structural Soil™ is a growth media designed to provide increased rooting volume for tree roots in plantings adjacent to pavement. It is a mix of crushed stone, clay loam and hydro-gel stabilizer that meets or exceeds compaction specifications for pavement base, yet allows tree roots to develop freely through it. The result is a revolutionary patented stone/soil urban tree mix that extends urban tree life and growth, optimizes root space under pavement, increases porosity and drainage, and provides a stable pavement base. Urban tree growth provides cooling, reduces air pollution, and provides natural habitats for birds and small animals.