ABSTRACT Many of the geological components of Bulgaria's coal waste-tips have properties which favour their conversion into soil. However, the regeneration of biological soil-forming systems can be very slow. Problems in the soil include severe summer soil moisture deficits, surface overhearing of dark coloured minespoils, erosion and layers of high bulk density at depth. These layers restrict root penetration and reduce permeability. Other obstacles include low levels of plant available nitrogen and phosphorous, sometimes exacerbated by low pH, low organic content and/or high levels of salinity, toxic concentrations of Fe, Al, and Mn, and locally pollution by Zn and the heavy metals: Cd, Pb, and Cu. The most effective way of establishing self-creating soil conditions is forest-biological recultivation. Results indicate that forestation may reduce the erosion of steep slopes by a factor of >3, and creates a soil of greater fertility and better structure. Forestation involves the selection of nitrogen fixing and deep rooting tree species supported by soil amelioration through mineral fertilization and the application of green manure. Nursery trees are planted at high density and managed regularly until organic activity becomes capable of generating a self-sustaining improvement of the environment.