A method for cultivating Monarda fistulosa for production of thymoquinone includes planting seeds at rates between about 2.5 and about 5 pounds per acre, preferably about 4 pounds per acre. The heavy rate of planting produces plants bearing oil without weed contamination and reduces herbicide use due to production of natural herbicides by the monarda plants. Seeding and mowing the first season, and harvesting in seasons thereafter reduce costs. The method results in increased production of essential oils including thymoquinone and thymohydroquinone at levels up to about 40% or more of recovered oils, and which may be distilled from the plant.