Plants can be used to remediate polluted soil or water ( phytoremediation) by extracting and / or degrading pollu-tants[1-2]and for stabilization of soils and ediments[3](phytostabilization) in order to prevent erosion and to minimize the re-lease of contaminants from the solid matrix. A broad range of inorganic and organic pollutants can thus be processed by usingsuitable plants that are tolerant of the pollutants, generate high biomass, and are effective in uptake. As an example, water hyacinths can be used for extracting and degrading cyanide from gold mining process water that usually contains cyanide spe-cies and heavy metals in concentrations of toxicological concern. We determined a lethal dose (LC50) of about 13 mg cya-nide / L for the water hyacinths and observed that under field conditions in a pilot scale wetland the plants became more effec-tive after several applications in degrading cyanide even at high concentrations. Experiments with radio-labelled cyanide re-vealed that the carbon and nitrogen of cyanide in the plants were used to biosynthesize asparagine; thus the toxic cyanide was effectively transformed into a non-toxic, natural product[4]. Waste disposal sites can be remediated with plants both with re-spect to leaching - the percolating water may contain high concentrations of pollutants and with respect to the stabilization of slopes in order to reduce erosion. We used the concept of dense vegetation on an industrial waste site and grew douglas firs that perform high evapo-transpiration rates throughout the year and thus reduce the amount of leachate from the dump site.For stabilization of the slopes it is possible to first install a stable, diamond-shaped network of living plants (willows), levelup the network with soil and spray a mixture of suitable seeds of grass, shrubs or trees (truck wet application) which will further stabilize the soil during growth. This technique can be applied also to river banks for erosion control.