Aquatrols wetting agents or "media surfactants" were first introduced to the horticultural industry over 25 years ago with the advent of "soilless" potting mixes. Wetting agents were added to bagged or baled peat-based media to ensure easy "wet out" or good "initial wetting" when first irrigated. Today, wetting agents are widely used in almost all horticultural growing media sold to greenhouses, nurseries, homeowners, or anyone who is growing plants in containers.

 

 

Soilless Media




    Soilless media (or "substrates") usually contain peat moss or bark as their major component (though coconut fiber, rice hulls, manure, or other organic substrates are sometimes used). In addition, they often contain vermiculite and/or perlite to aid in drainage, and limestone to help regulate pH levels. Different combinations of media components are used to meet different growing requirements. Examples include very fine media for small plants or seedlings grown in very small containers, coarse media components for enhanced drainage when growing woody ornamentals or large foliage plants outdoors, highly acidic substrates for growing specialty plants such as azaleas, or "general potting soil" for homeowners and hobbyists growing typical indoor potted plants or outdoor vegetables in containers. For any given plant or growing condition there are usually many types and brands of acceptable media available, but all would share one common characteristic were it not for the use of wetting agents: an inability to rewet uniformly after drying.


    Med    ia that dry out commonly fail to rewet properly for a number of reasons.  Waxes, resins, organic acids, and other chemicals present in organic media components are inherently water repellent.  When peat moss or bark in media dries out, these chemicals are exposed to air, which causes them to become even more water repellent.  (Remember - part of the job that bark did on the tree was to keep water and chemicals inside of the tree, and diseases, rain, insects, etc. out!).  Water repellency ("hydrophobicity") is a condition that prevents water from adhering to and moving uniformly into and through a medium.  The reason media do not wet consistently is that the particle surfaces and pores within these media are constantly changing every time they undergo wet-to-dry cycles.

Industry Links:

Peatland Ecology Research Group (PERG)