Capillary Action

What Does Capillary Action Mean?

Capillary action is a liquid's (e.g., water) ability to flow through substances in a series of various capillary channels or tubes. Water can be drawn up through a plant's vascular tissues (xylem and phloem) via capillary action, although transpiration also plays a significant role.

Capillary action may also be known as capillary force or wicking.

Maximum Yield Explains Capillary Action

A plant's roots spread throughout the soil's capillary channels and have the ability to take in water by drawing it up.

Soil, rocks, wood, and other seemingly solid minerals contain tiny spaces (capillary tubes) through which water flows and from which roots draw their water. The movement of water through these tubes is the capillary action or wicking.

In rocks, the fissures that move water are so minuscule that they are not visible to the naked eye.

Capillary action is constantly occurring as water moves through the soil. When rainfall hits the soil it is drawn downward and sideways by capillary action. During dryer periods water is drawn back up via this same action.

During the heat of the day, capillary action draws water up to the surface where much it evaporates. In nature this process is slowed by fallen leaves and other naturally occurring organic mulches and ground covers. In the garden this evaporation is slowed by the intentional application of mulch or other organic matter.