Introduction: Due to the water shortage and location of Iran within an arid region, the total costs of maintaining urban green space is dramatically high. Most of the plant species cultivated in the urban green spaces of Iran are exotic and need a high amount of resources. Native species, in contrast, are adapted to the soil conditions and temperature fluctuations, and also need much less water.Materials and methods: This research was aimed at the domestication of Melica persica Kunth, a perennial grass native to the mountains around Mashhad city. This species was considered because of being native and also for its attractive inflorescence and growth form. Seeds of M. persica were collected from Dehbar village (14 Km from Torghabe- Shandiz, 59 17' 23" N, 36 15' 04" E) in July 2014 and planted under three germination treatments within a germinator (in 23-27 °C), in pots (green house) and by direct seedling transplanting.Results and discussion: The germination and growing percentages for these treatments were 96, 58/5, and 25/5 percent, respectively. All the plants were cultivated in Ghadir nursery in Mashhad. The survival rates of this species were recorded under two treatments of pot and direct plantings. The phenological stages were monitored during the growth season of 2014-2015, both in the natural habitat and within the Ghadir station at Mashhad. In the two years of 2014 and 2015, temperature, time and number of days were different. The different stages of phenology, such as early flowering, flowering and seeding received the same GDD. The energy required each phenological stage in the different years was almost the same and, if there was any between them it was because it was not possible to go daily to the growing areas and record the phenological stages. There were just differences in transplanting and direct methods and this could be due to the different conditions of the plant and environment. Researche studies by Azimi et al. (2012), Azarnivand et al. (2012)and Mirhaji and Sanadgol (2007) on the effect of growing degree-day (GDD) and soil moisture on Stipa hohenackeriana in arid and semi-arid regions of Iran, on the effect of GDD on phenology and growth of Onobrychis melanotricha, and on the whole required temperature range for phenological stages of a number of important species in the grasslands research station Homand showed that environmental factors such as temperature, rainfall and humidity can influence these stages. The phenological stages were almost similar under the three treatments, in other words they were totally dependent on the seasonal changes in temperature. An important point in the phenology of Melica persica was seen both under natural conditions and in the test site (Ghadir station, 59 36' 55" N, 36 14' 31" E), re-growth during autumn occurred for those plants growing at the Ghadir station, which was well irrigated, but not for plants growing within the natural field; these results showed the degree by which water is more available for plants, it effects the freshness of the plants and causes them to grow longer.Conclusions: Results of this research indicate the possibility of domesticating M. persica for sowing it in the urban green space. M. persica could be suitable for rock gardens and mountain views because of its form. The best method for planting this species is by transplanting. The percentage of germination, establishment and survival was good and attractive in spring and summer and autumn.

One of the social and citizen demands that is increasing in developing countries, is the expansion and rehabilitation of urban green spaces. Population growth and lack of sustainable water resources is one of the important challenges facing the arid regions. Change in style and paradigm of landscape design in arid areas with regard to the priority of reducing water consumption, can lead to social discontent caused by xeriscaping and creation of low input green spaces. Rising visual demand in society towards green spaces in recent decades as a result of improper selection of landscape design patterns, especially in dry areas, is the main reason for a possible conflict between aesthetic preferences and sustainable green space in these regions. In xeriscaping, integration of effective factors in aesthetic perception with relevant variables in planting design less has been under consideration. Effective factors in aesthetic perception are nine visual concepts include coherence, disturbance, stewardship, imageability, visual scale, naturalness, historicity and ephemera. Seven fundamental principles of xeriscaping are plan and design for water conservation, improve the soil, limit turf area or select alternatives, irrigate efficiently, select appropriate plants and hydrozone plants, mulch to reduce evaporation, maintaining a xeriscape. Despite researches showing that xeriscaping could usually reduce landscape water consumption by one-third however, many people were initially reluctant to substitute it for conventional landscaping. A common perception was that xeriscape were drab and barren and featured nothing more than rocks and some succulent and thorny plants. In this paper, on one hand the aesthetic preferences of landscape and green space and also options of design in arid regions of Iran have been explored and on the other hand, the reasons behind possible confrontation between these two major issues and suitable strategies for reducing the conflict, has been discussed and analyzed. Amongst the nine concept of aesthetic that affect social preferences, the concepts of complexity, coherence, imageability and ephemera in green spaces of arid regions, are faced with more challenges than other concepts. Since in the xeriscaping, use of drought-resistant plants is one of the principles so, for low diversity in ornamental plant species and partial removal of lawns and water element in the landscape, aesthetic preferences of citizens, will not be fulfilled completely. Social awareness toward the water crisis in the arid and semi-arid regions of Iran, ornamental plant domestication and import of drought resistant species as alternatives and also creativity and innovation in xeriscaping designs, can decrease the possible dissatisfaction of the citizens from the sustainable and rational development of green spaces in dry climates.

In this study, ornamental potential and acclimization of three Achillea species were assessed under Isfahan climate conditions. Three accessions of A. millefolium, two accessions from endemic species of A. pachycephala and one accession of A. filipendulina were studied in a randomized complete block design (RCBD) with 6 treatments, 3 replications and nine important ornamental characteristics were recorded. The results showed that different accessions have different ornamental potentials. The results of cluster analysis based on mean of each character, classified the genotypes into three groups. Group 1 included Iranian A. millefolium accessions [A. millefolium (40) and A. millefolium (35)]. Group 2 consisted of three genotypes including A. millefolium. f. rosea from Lithuania, A. filipendulina from Ardebil and A. pachycephala from Hamedan. A. pachycephala from Golestan was separated from other genotypes and classified in the third group. Among accessions, A. pachycephala from Golestan had excellent potential for using as ground cover species, while other genotypes were good candidates as border and bedding plants in landscape and xeriscape. A. filipendulina genotype from Ardebil had the most number of floret in inflorescence, plant height and flowering time duration. Three genotypes belonged to A. millefolium, had sufficient variation in order to be selected as ornamental species for landscape design. Finally, different Achillea species were suitable in landscape, because of their tolerance to environmental stress, beautiful flowers, color diversity and different flowering times.