We have conducted a systematic study on the herb Centella asiatica, planting according to VIETGAP and ORGANIC methods in central Viet Nam over twenty-six months with fifteen harvests for each method. The study examined the ratios of the dry mass to the fresh mass of the herb, the ratios of the raw ethanol/water (80:20 v/v) extract to the dry mass, and the contents of three main biologically active triterpenoids madecassic, asiatic and terminolic acid in the extracts before and after the alkaline hydrolysis of the extract.