Composts prepared from sewage biosolids-wood chips, mixed municipal solid wastes, autumn leaves, mixed yard wastes, or agricultural wastes were assessed for their effects on growth and composition of perennial ryegrass (Lolium perenne L. ‘Pennfine’). Two biosolids based composts, one mature and one immature, were evaluated. All of the other composts were mature. No supplemental fertilization was provided. Composts were evaluated without amendment or by mixing with soil and sand to create media (proportions by volume) of 100% compost, 90% compost:10% soil-sand, and 75% compost:25% soil-sand. Grass sods were grown in plastic flats in a greenhouse. Quality of sods was assessed by emergence of grass and weeds and by clipping mass in two successive harvests. Macronutrients, micronutrients, and nonessential elements were determined in the grass clippings of each harvest. Grass emergence was lowest in the mixed municipal solid waste compost, which had the highest soluble salt contents of the media. Slight inhibi...