Construction and demolition wastes (CDW) are being explored as a viable alternative material for geo-environmental applications, including embankment fill material for roads and railways. However, there are still limitations to CDW use, specifically on its environmental effect. Maintaining a well-balanced relationship between construction and the environment is crucial to avoid ecological problems. Hydrochar obtained through hydrothermal carbonization can adapt CDW for the growth of plants needed to stabilize CDW embankment slopes. Given the highly alkaline nature of CDW and its potential environmental impact, hydrochar presents a possible solution to improve the efficiency of CDW as an embankment material and plant medium. However, there is a lack of research to prove the feasibility of using hydrochar to fully utilize CDW in transportation engineering applications through greening. In this study, hydrochar was produced from peanut shell and wood biomass at 250 °C and 1 h of residence time. To assess the chemical and physical properties of hydrochar for CDW remediation, pH and electrical conductivity tests, proximate analysis, surface area and pore volume tests, and Fourier Transform Infrared Spectroscopy were conducted. Compaction tests were also conducted on the hydrochar-amended CDW. The acidic nature and porous structure of hydrochar have significant implications for positive improvement of CDW properties.