The aim of this study is to investigate the difference between the growth of plants with and without mycorrhiza in vegetation studies that will be conducted in arid regions. In order to determine the effects of mycorrhiza, Forsythia x intermedia plant was chosen because of its wide usage in Landscape Architecture application studies due to its esthetic and functional properties and because of its common existence in dense-massive vegetative designs. Forsythia x intermedia plants were planted in Soil (S), Soil + River Sand (SS), Soil + River Sand + Organic Matter (SSO) medium at three application areas with different annual rainfall values. By taking measurements once in every three months; the heights, diameters and number of leaves were determined. In the 6th and the last measurement period, plants were taken from the roots of the plants and mycorrhiza colonization percentages were calculated. At the end of the research it was found that the plants with mycorrhiza had the largest height and diameter values at Gumushane application area in SSs media, at Macka application area in SSOs media and at Trabzon application area in SSO media. Mycorrhizal plants with the most number of leaves were at Gumushane application area in SSOs media, in Macka and Trabzon application areas at SSO media. The highest mycorrhiza colonization percentage values were obtained at Gumushane application area in SSO (52.78%) and SSOs (41.16%) medium as compared to values obtained from other areas.