Abstract. Achillea spp. is one of the most important medicinal genera belonging to Asteraceae family. The potential of this genus as low maintenance and water consuming ground cover species compared with turf grasses can make its application in urban green space planting promising. However, the ornamental potential of the genus yet to be investigated. In this research, in order to determine ornamental potential of six Achillea species (Achillea millefolium, white and pink flower species), A. biebersteinii, A. santolina, A. nobilis and A. filipendulina ), the seedling of these species were cultivated on a Horticultural Department Research Field of Ferdowsi University of Mashhad in October 2009. Phenological and morphological characteristic of theses species at different growth stages were recorded. This experiment was conducted in a factorial completely randomized design (RCBD) with 6 treatments (Achillea species) and 3 replicates. Based on gained results A. filipendulina, an imported species to Iran, successfully compatible with green space of different regions of Iran together with A. millefolium (white flower), was evaluated as a superior species. These two species had an average height of 90 cm, and their flower lasted for a relatively long period (approximately 60-70 days) and had larger coverage area compared with the other species. These characteristics made these species more suitable than other studied species in this experiment for ornamental and ground cover planting purposes. Other four species were in a moderate level in terms of their ornamental potential.

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