In this paper we propose a typology of patterns -or composition systems- for the morphological definition of horizontal surfaces in landscape design. Specifically, we state that the basic ways to define such horizontal surfaces in landscape design fit four possible composition systems or organizational patterns, which we will call Carpets, Paths, Mosaics and Strata. After identifying the characteristic and differential features of each of these patterns, which we will validate by contrasting them with exemplary works taken from historical and contemporary landscape architecture.