Background and objective: This study aims to provide basic data to investigate an efficient and stable environment for indoor urban agriculture by comparing plant growth depending on seeding rate and media nutrients (nitrogen, phosphorous, and potassium) using leguminous plant <i>Medicago sativa</i> favorable for nitrogen fixation and Lamiaceae plant <i>Perilla frutescens</i> in indoor urban agriculture.Methods: To investigate plant growth by mixed seeding rate, this study set up 6 treatments: single seeding of <i>M. sativa</i> (AC); 2 : 1 <i>M. sativa</i> to <i>P. frutescens</i> (A₂P₁); 1 : 1 <i>M. sativa</i> to <i>P. frutescens</i> (A₁P₁); 1 : 2 <i>M. sativa</i> to <i>P. frutescens</i> (A₁P₂) and single seeding of <i>P. frutescens</i> (PC). Experimental plastic containers were completely randomized designed with 9 replications for each seeding rate. Nutrient content of the media and germination and growth parameters of <i>P. frutescens</i> were measured.Results: The nitrogen and phosphorous contents in the media were the highest in the AC treatment, and potassium did not differ according to the mixed seeding rate. Germination percentage and velocity were highest in order of A₁P₂ > PC > A₂P₁ > A₁P₁ > AC due to interspecies competition. Growth of <i>P. frutescens</i> was increased with the increasing seeding rate, whereas biomass was higher in A₂P₁ compared to other treatments.Conclusion: Our results indicated that the 2:1 seeding rate of <i>M. sativa</i> and <i>P. frutescens</i> was a more effective way to achieve high plant growth and productivity. These results suggest that mixed seeding can promote the interaction of positive neighbor effects in indoor urban agriculture.