<p>Increasing crop density is an effective cultural practice for weed management. An experiment was conducted at two locations (Alburgh, Vermont and Aurora, New York) in 2022 and repeated in 2023 to assess the effects of black bean (<i>Phaseolus vulgaris</i> L.) seeding rates on weed suppression, yield, and economic returns in organic production. Five seeding rates were compared that ranged from 148,300 to 926,600 seeds ha^− 1. Black bean density at harvest increased with seeding rate but tended to deviate more from target densities at higher rates due to self-thinning. Weed biomass declined and yield increased asymptotically with increasing black bean density. An economic analysis indicated optimal seeding rates for maximum returns were over 500,000 seeds ha^− 1 across all four site-years. Although yield gains tended to be modest at higher densities, the relatively high pay price of organic black beans justified the additional seed costs. However, under the wetter and more humid conditions observed in 2023, white mold incidence increased with increasing black bean density, particularly at densities exceeding 500,000 plants ha^− 1, highlighting potential tradeoffs associated with elevated seeding rates. Future research should evaluate the effects of increasing black bean density across a wider range of environments, including those with different weed communities and levels of disease pressure.</p>