Cover crops and organic mulches are reducing soil inputs and increasing the quality of soils. Using mulches as a thin and separate cover for the soil surface, can cause soil, water and plant protection and reduce environmental pollutions. Many studies have been carried out on the effects of organic mulches on soil physical, chemical and biological properties; however there are only few researches on this subject in Iran. The objectives of this work were to study the effects of two woody mulches on soil physical and chemical properties and to determine the yields of two plants Zinnia elegans and Verbena hurida under different mulch treatments. A pot experiment was conducted in a completely randomized design with a factorial combination and three replications. The treatments were consisted of two types of plants ( Zinnia elegans and Verbena hubrida ), two types of mulches ( Fraxenius excelsior and Ulmus carpinifilia ) with two thicknesses (3 and 6 centimeter) and a control. During the plant growth period, some morphological characters such as the shoot height, stem diameter and number of flowers were recorded. At the end of growth period, the dry weight of shoots and roots was also measured. Plant irrigation was scheduled at 25% of available water consumptio with distilled water using a Time Domain Reflect meter (TDR). Results showed that, the organic mulches decreased the water consumption, significantly; whereas pH, EC, calcium carbonate, soluble sodium and soil bulk density decreased in mulch treatments. Organic matter content, total nitrogen, soluble phosphates, available potassium, soluble calcium and cation exchange capacity increased in the mulch treatments. The mulch treatments also caused higher plant biomass and higher nutrient uptake over the control. The increase was more significant in 6 cm than 3 cm mulch thickness. The increase in shoot biomass, over the control, were 18% in Zinnia elegans and 52% in Verbena hubrida. The increase in root biomass were 13% and 64% for Zinnia elegans and Verbena hubrida, respectively in 6 centimeter mulch thickness. The elemental analyses of the mulches at the beginning and at the end of the experiment showed that the soluble calcium, sodium, sulfate and the total copper content of the mulches decreased by the end of the seaso whereas, the soluble phosphorus, organic carbon, available potassium, manganese, zinc and magnesium decrased. These changes were all statistically significant. In conclusion the organic mulche increased the plant yield and improved the soil physical and chemical properties, while the changes were sharper at 6 cm of the mulch thickness. Keywords : soil coverage, waste management, recycling, wood mulches, water use efficiency