A two-year field experiment was conducted during the dry seasons of 2007/2008 and 2008/2009 on the acidic coastal plain soils of south eastern Nigeria to evaluate the effectiveness of organic mulch on the productivity of maize (Zea mays L.) and weed growth. Five mulch rates (0, 2, 4, 6, and 8 t/ha) were laid in a randomized complete block design with four replications. Soil moisture reserves were highest at the 8 t/ha mulch rate, followed by 6 t/ha rate. The unmulched control plots had the highest weed infestation, lowest soil moisture reserves, shortest plants and least number of leaves/plant. Weed infestation at the unmulched plots were higher by as much as more than 6 and 11 times those at 6 and 8 t/ha rates respectively. Plant height and number of leaves/plant were maximized at 8 t/ha rate, while dry stover yield, weight of grains/cob and grain yield/ha peaked at 6 t/ha rate. The grain yield obtained at 6 or 8 t/ha rates was more than double that of the unmulched control plots.