Grain amaranth (Amaranthus spp.) is a C4 dicotyledonous pseudocereal crop that was widely cultivated in pre‐Columbian America. It was successfully introduced in many regions with contrasting environmental conditions. The introduction of grain amaranth in eastern Canada would represent an opportunity for diversification. A study was conducted to evaluate management practices for grain amaranth grown in this region. Three field experiments replicated in three environments were conducted to evaluate the following factors: (i) seeding date (mid‐May, early‐June, and mid‐June) and cultivar (K432, K593, and Plainsman); (ii) row spacing (38, 58, and 76 cm) and seeding rate (1, 2, and 4 kg ha−1), and (iii) N fertilization rate (0, 50, 100, 150, and 200 kg N ha−1) and cultivar (D136 and Plainsman). Seeding date affected grain yield in only one out of three environments, with the earlier date resulting in the highest yields. Cultivars differed in yield in only one of three environments, with Plainsman resulting in highest yields. Later seeding dates resulted in higher seed moisture at harvest in all environments. Seeding rate and row spacing did not affect grain yield, but row spacing affected grain moisture at harvest, with narrower rows resulting in grains with lower moisture content. Nitrogen fertilization increased yield and lodging in only one environment. Seed moisture and plant height were positively related to N fertilization in all environments. Cultivar D136 yielded more than Plainsman in 2005 and less in 2006. Therefore, grain amaranth production in eastern Canada seems possible, management practices having limited impact on grain yield, which averaged 923 kg ha−1 across all experiments and environments.