A two-year field study was conducted to evaluate the impact of fertilization and arbuscular mycorrhizae on the in situ establishment of turfgrasses in low and high phosphorus content experimental sites. Organic or chemical fertilizers were applied on Kentucky Bluegrass and Creeping Bentgrass plots inoculated with either Glomus mosseae, G. aggregatum or G. intraradices. The arbuscular mycorrhizal control was made from original soils with their respective indigenous fungal populations. Soil surveys for indigenous Glomales populations revealed the predominance of Gigaspora margarita and Scutellospora calospora species at the high and low P sites, respectively. Both turfgrass species showed higher root colonization levels, up to 60%, at the low phosphorus soil site. Root colonization levels of Creeping Bentgrass were found to be almost twice those of Kentucky Bluegrass for all mycorrhizal treatments. The average growth rates of aerial parts were not affected by either mycorrhizal or fertilization treatments. Statistical analyses showed a significant interaction (P ≤ 0.05) between high and low phosphorus sites for Creeping Bentgrass, and root colonization levels, especially with G. intraradices treatment. For both turfgrass species, fertilization and site effects were predominant. As turfgrass is highly dependent on soil quality and as arbuscular mycorrhizal benefits vary with plant species, special cam in the development of turfgrass management practices should be taken into account to optimize the arbuscular mycorrhizal turfgrass establishment process. [ABSTRACT FROM AUTHOR]