Oregano is a common ingredient in Italian sauces to sandwiches. When grown in your garden, oregano is a perennial plant that should be grown in zones 5 through 9. Planting your oregano transplants should be done in either spring or fall. At any time of the year, the soil needs to be well-drained and the plant needs full sun. Oregano can get to be 24 inches tall and, in your garden, they should be added every 18 inches. Containers are another option for planting oregano.