How to reduce overwatering of growing media

Water is essential for plant growth and development. Water is used by plants for transpiration (to lower leaf temperature), it acts as a solvent, it is involved in chemical reactions like photosynthesis, and it transports nutrients through the plant. The purpose of watering a plant is to replenish the water that was used by the plant for the above actions and to leach salts from the growing medium.

Watering frequency and duration (amount of water) depend on the plant species, the stage of plant development, the growing medium selected and the growing environment. Water management is problematic when there is plant damage from overwatering or underwatering.

Typically, when a plant is overwatered, the leaves turn chlorotic, plant growth is stunted, algae start to grow on the surface of the substrate, the root respiration rate decreases, and the roots are more susceptible to root rot diseases like Pythium, Fusarium, Rhizoctonia and Alternaria.

On the other hand, when a plant is underwatered, transpiration ceases, the leaves are no longer turgid, nutrients, such as calcium, do not go to the furthest parts of the plant (this creates blossom end rot), the plant is under hydric stress, and growth and development are negatively affected.

Read more at PRO-MIX (Jose Chen Lopez)