The growing demand for container ornamental plants opens new opportunities for nurseries to expand their business. However, expecting to improve plant quality, growers often overapply fertilizer and water. Excessive fertilizer application and overwatering can result in nutrient leaching and runoff. In addition, growers heavily rely on unsustainable sphagnum moss as a medium for growing their plants. Replacing sphagnum moss with coconut coir may increase production sustainability, and incorporating biochar may have potential to adsorb excess nutrients, thus lowering fertilizer concentration in leachate. In this study, we explored the suitability of using various mixtures of coconut coir and biochar for growing goldenrod, lavender, and chrysanthemum plants for two growing seasons. Results indicated that utilizing pine bark and coconut coir did not hinder plant growth and development compared to a traditional mixture of pine bark and sphagnum moss for any of the plants studied. Also, inclusion of 10% biochar did not enhance growth, nor did it reduce nitrate nitrogen and phosphorus concentration in container leachate. Biochar did not reduce nutrient leaching in this study. However, coconut coir was found to be a suitable substitute for sphagnum moss in container nursery production.
