Capillary
/ˈkæpəˌlɛri/
Definition
Capillary describes the movement of water through very narrow spaces because of adhesion and surface tension, often called capillary action. In plants and gardening, it explains how water can rise through fine pores in soil, potting mix, paper, or the tiny water-conducting tubes of xylem without pumping. This is a physical process, not a separate plant structure, and it depends on small pore size and close contact with water.
Role and Significance
- Water movement in narrow spaces: In plants, capillary action helps water spread through tiny pores in cell walls, soil particles, and potting mixes. This supports short-distance moisture movement around roots and through some tissues.
- Part of a larger transport system: Capillary forces contribute to upward water movement, but they do not explain the full rise of sap in tall plants. Transpiration pull and the cohesion of water molecules do most of that work.
- Influence on rooting media: In propagation trays and containers, capillary behavior affects how evenly a medium wets and dries. Fine-textured mixes tend to hold water higher and longer than coarse mixes with larger air spaces.
- Importance in watering methods: Bottom watering and capillary mats rely on this process to draw moisture upward into the root zone. These methods can improve even moisture, though they still depend on a suitable potting mix and drainage.
Related Terms
Capillary action
Capillary action is a physical process in which water moves through narrow spaces because the water molecules stick to…
Wicking
Wicking describes the movement of water through a porous material by capillary action, the same force that pulls…
Osmosis
Osmosis is a biological process in which water moves across a selectively permeable membrane, such as a plant cell…
Bottom watering
Bottom watering refers to a watering technique in which a pot is placed in shallow water so moisture moves upward…
Self-watering pot
Self-watering pot refers to a container designed for growing plants with a built-in water reservoir below the root…
Watering
Watering is the horticultural practice of applying water to soil or growing media around plants, or less often directly…
Drainage
Drainage describes how quickly excess water moves out of soil or a potting mix after watering or rain. In horticulture…
Soil
Soil is the natural surface layer of land where most plants root and grow. It is a living mixture of mineral particles…