<p><strong>Background</strong>: The production of high quality seedlings locally is an area of opportunity for the development of organic agriculture in south-southeastern Mexico. In the case of jalapeño bell pepper production, a vegetable with high demand for national and international consumption, the use of alternative substrates to produce organic seedlings is a necessity in tropical and subtropical regions. Biochar combined with organic amendments has been shown to be potentially beneficial in a variety of crops in support of organic agriculture. <strong>Objective</strong>: To evaluate the effect of biochar used in combination with bocashi to produce jalapeño bell pepper seedlings. <strong>Methodology</strong>: Seven treatments were defined, biochar at 10, 20, 30, 30, 40 and 50 % + bocashi, plus two controls, a commercial organic fertilizer (peat most at 70 % + perlite at 30 %) and another natural soil of the region (alluvial soil). The research was descriptive and under a completely randomized design the systems were exposed with four replicates, each experimental unit was represented by 33 cavities in germination trays of 77 spaces, in each germination tray two replicates were established. The biochar was activated with efficient microorganisms through an anaerobic fermentation process. Hybrid jalapeño bell pepper seed was used. A total of 132 seeds were sown for each treatment in 924 planting points in total. Management consisted of daily irrigation. In addition, a foliar biofertilizer based on a mixture of efficient microorganisms and earthworm leachate was applied weekly. The variables evaluated were days to emergence, number of leaves, plant height, stem diameter, total length, green and dry weight of seedlings. ANOVA and Tukey's mean tests were performed. <strong>Results</strong>: The use of biochar mixed with bocashi in its different proportions benefited seedling emergence and gave better results in the variables evaluated than the controls. The proportions with the highest percentage of bocashi excelled in all variables. <strong>Implications</strong>: The combined use of biochar with bocashi represents a substrate with potential to produce organic seedlings of jalapeño peppers in the subtropical regions of south-southeastern Mexico. <strong>Conclusions</strong>: The combined use of bocashi (80%) and biochar (20%) constitute a technically feasible alternative for its implementation in the production of jalapeño bell pepper seedlings. This research contributes to the development of organic agriculture in the south-southeast of Mexico.</p>