Reviewed by Specialty Soils Updated August 21, 2026
Roots need both water and oxygen. A root zone can contain plenty of water and still perform poorly if air exchange is inadequate.
Drainage is more than the surface
It is not merely how quickly water disappears from the top. The arrangement of pore spaces throughout the root zone matters.
Pore sizes serve different roles
Fine pores tend to retain water more strongly. Larger pores tend to drain more readily and refill with air. A useful medium balances both for the crop and management system.
The system interacts
Particle size, container geometry, irrigation, and material choice cannot be evaluated in isolation.
Apply the science to a real growing system
Container dimensions, crop, irrigation and duration should lead the material decision.
Sources & references
General horticultural guidance is supported by the following authoritative resources. Specialty Soils product statements and labeled company observations are first-party information.