Oregano is a plant which needs frequent watering in order to thrive. A plant that has been over-watered will wilt and die. Plants need water in order to produce food and oxygen. The more they are watered, the better the food quality and the more oxygen that is produced. If plants are not watered, they stop producing food and oxygen. A plant that has not been watered is unhealthy. A healthy plant has water in the soil. An unhealthy plant does not have water in the soil.