Abstract: Methods for producing heterologous terpenes, terpenoids and/or small molecules in transgenic glandular trichome-bearing plants are provided, as well as the transgenic glandular trichome-bearing plants capable of producing the heterologous terpenes, terpenoids and small molecules. The genetically engineered glandular trichome-bearing plants contain and express one or more genes which encode proteins active in the biosynthetic pathways which produce the terpenes, terpenoids and small molecules. As a result, the essential oil of the transgenic plant is enriched for the heterologous or homologous terpenes, terpenoids and/or small molecules Storage of the essential oil in the glandular trichomes of the plant reduces the volatility and cytotoxic capacity of the heterologous molecules, thereby increasing yield and decreasing damage to the transgenic plant.