Sustainable plant production needs to monitor the development of plants, which are important in terms of food, medicinal, and aromatic properties, in different volumes and nutrient media, and to determine their ability to adapt to different ecological environments.For this purpose, the Cuban Oregano Plectranthus amboinicus (Lour.) plant was chosen as study material. The aim of this study is to determine the effect of organic worm manure and peat applications on the development of the plant of Plectranthus amboinicus (Lour.) in different pot sizes and different media. For this purpose, pots of 3 different sizes and volumes (250, 450 and 700 cc) were filled with commercial peat. Later, randomly selected Cuban Oregano seedlings were planted in pots filled with peat. 8 different doses (peat +10 g vermicompost+ 30 ml vermiwash, peat +10 g vermicompost + 10 ml vermiwash, peat + 15 g vermicompost + 10 ml vermiwash, peat + 20 g vermicompost + 10 ml vermiwash, peat + 10 g vermicompost were applied to seedlings planted in pots, and peat only applications were made as control group. As a result of the research, the best development according to the media was obtained from the experimental plots where 10 grams of vermicompost was applied. The best plant development according to the pot sizes was obtained from the 450 cc pot. The highest leaf surface area by 9.33 cm2 was found in a 450 cc pot, while the highest belowground biomass was found in 700 cc pot and peat medium in T5 treatment where 10 g vermicompost was applied. In addition, increasing the production of medical-aromatic and high landscape value plants can contribute to the success of rural development studies and the development of the national economy.