Mexican Oregano is not true Oregano, it's not even the same species and is more closely related to Lemon Verbena. Although it shares a similar trenchant flavor with true oregano it also has a hint of a citrus twang.
It is also not as hardy as true oregano and only grows as a perennial in Mexico , the American Southwest and some hot dry southern regions [USDA zones 7b and 11.] it can be grown as an annual elsewhere that has reasonably long warm summers.
It is suitable for indoor gardens so long as the temperature is kept above 50 F and ample light is provided.
Mexican Oregano produces visually pleasing fragrant purple flowers in the spring that keep giving right through Autumn. Dead Heading the flowers enhances more flower production.
Mexican oregano can grow into fairly large bushes when properly cared for. Well drained fertile soil, adequate but not excessive moisture and at least 6 hours of light daily but preferably more. Prune them back lightly in the spring to keep them bushy and compact.
Mexican oregano leaves can be harvested at any time. It is used for any recipe that calls for oregano or marjoram but keep in mind that it is sweeter, slightly citrusy yet more robust that standard oregano. In parts of Mexico and Belize, a small central American country, it is sometimes called 'te de pais' meaning country tea and it is used to brew an herbal tea.