Subirrigation, a technique where plants absorb moisture from below, involves placing potted plants in a water-filled saucer or basin, allowing water to move upwards through the soil via capillary action. This method contrasts with traditional top-watering, where water is applied to the soil surface. An example includes setting a plant in a container filled with an inch or two of water for a period, enabling the soil to saturate from the base.
This watering approach promotes deeper root growth as roots actively seek moisture at the bottom of the pot, contributing to stronger, healthier plants. Furthermore, it reduces the risk of fungal diseases and pest infestations by keeping foliage dry and minimizing surface moisture. Historically, variations of this technique have been employed in agriculture and horticulture to optimize water usage and improve plant health.