The present research was carried out to determine the influence of different combinations of organic matter as growing media on seed germination, survival, growth, biomass and performance of needle-leaved arizona cypress (Cupressus arizonica var arizonica Greene) and medite cypress (C. sempervirens var. horizantalis (Mill.) Gord) seedlings in a forest nursery located in northern Iran. Seeds were sown in plastic pots as randomized completely block design (RCBD) with four replications at four different soil treatments, including: T1) nursery common soil (control), T2) control soil: cattle manure (5:1), T3) control soil: decomposed litter (5:1), T4) control soil: cattle manure: decomposed litter (5:1:1). The results after one year showed that seedlings of both species grown on T4 obtained better germination percent, survival, shoot height, collar diameter, seedling vigor index and Quality Index (QI). Greatest relative growth rate (RGR) of height and diameter were achieved on organic matter treatments. In most of the studied attributes, response of C. arizonica was better than C. sempervirens, showing the different ecological requirements of these species. From the study, it is concluded that the increased availability of soil nutrient can be useful in seedling production of both species.
