Maximum Yield USA March 2017 | Page 110

tips & tricks

Those small white particles we have all seen in potting mixes really do have an important role to play , though we may often take them for granted . They are called perlite and work to prevent the soil from becoming compacted . By doing this , perlite functions as an aid to maintain adequate air or oxygen in the soil , which in turn improves plant respiration . To better understand whether perlite is right for your growing operation , it is best to look a bit deeper into just what it is and what it does . Non-combustible , perlite is essentially expanded glass that is retrieved from areas where a volcano has been active . Perlite is initially quarried , crushed , and then fractionated or divided up into its various parts : those that will be capable of being expanded into useful perlite , and those that are not . The useful form of the product will have a typical grain size between 0.14 and three millimeters . These particles will later be expanded at high heat to give the final product its airy texture . Perlite is non-fibrous , which makes it safe for use . However , it can contain perlite dust particles , so it is best to work with it moist to prevent the inhalation of these particles .

If your grow pots are sheltered from wind , perlite placed on the surface of the grow media will wick away moisture from the surface and reduce or eliminate mold and moss .”
Nutrient-rich water is attracted to the small crevices in the perlite , and this capillary feature is why it can also provide moisture to your plants as well as aid in providing oxygen . Whether to use perlite or not greatly depends on what type of grow system is being used . Regular soil is an obvious candidate as it is quite heavy and can become compacted . Some organics like peat moss or cocoa mulch can and will also compact . This happens over time as the soil or media is watered ; each particle gets closer to the others and air pores are shrunk or eliminated . When this happens , water will not drain through the grow media very well and air will not easily penetrate . The grower will likely notice a decrease in plant vigor and production , though they may not be aware of the cause . Roots also may fail to expand or grow , and they may contract various diseases due to a lack of oxygen and overabundance of moisture . Moss can grow on the medium ’ s surface if it remains wet most of the time . Perlite makes a positive
108 grow cycle