The effects of addition of coirpith compost (CPC) (5-25 g/3 kg of soil) on the above-ground (plant height, number of branches and leaves, leaf area and weight of the leaves), and below-ground (root length, number of roots and weight of the roots) parameters and the quality of leaves (chlorophyll and nitrogen) were studied. The responses of the various parameters to addition of increasing quantities of CPC were different. Compost at 5 g or more per 3 kg soil produced a significant increase over the control in the number of roots. At 10 g compost or more the length of roots and nitrogen content of leaves were increased, while 15 g or more increased the wet and dry weights of roots. At 20 g or 25 g the plant height and wet and dry weights of leaves were increased, whereas only 25 g compost increased leaf chlorophyll and the number of branches and leaves. Excepting individual leaf area, which did not show a statistically significant increase even with the 25 g compost treatment, all parameters recorded the greatest response at 25 g compost. Considering the influence in increasing the growth and quality of leaves, CPC supplementation is recommended for mulberry cultivation.