The experiment was conducted at National Horticultural Research Institute, Ibadan and Ladoke Akintola University of Technology, Teaching and Research Farm Ogbomoso between August and December, 2015. Five accessions of grain amaranth were screened in the field at both locations. The trials was laid out in Randomized Complete Block Design (RCBD) was used in assigning treatments in the field and replicated three times. Seven Nitrogen sources: poultry manure, cow dung, pacesetter organic fertilizer, brewery waste, providence organic fertilizer, Aleshinloye organic fertilizer N:P:K and control each applied at 120 kg N ha-1 imposed on the five selected accessions. Data were collected on growth (plant height, stem girth, number of branches and number of leaves) biweekly and subjected to analysis of variance. The results shows that, irrespective of the accessions, the two agro-ecological zones are suitable for high grain yield of grain amaranth but Ogbomosho; derived savannah zone gave better growth biomass than the transitional rainforest ecology of Ibadan in grain amaranth production. To improve the growth of amaranth, addition of fertilizer up to 120 kg N ha-1 is recommendedpreferably organic fertilizer like cow dung.