By Dan Jacques and Ron Walden, Sun Gro Horticulture –
The major role of a growing mix is to support the plant, while holding water and nutrients for the plant to use during growth. There are five main components commonly used in making growing media: peat moss, bark, coir, perlite and vermiculite. This article describes the components and outlines desired properties of mixes for various uses in greenhouse production.
“For growers who desire low EC levels and do not want to leach the ideal solution is the use of growing media products with reduced nutrient charges.”
The measurement of soluble salts tests the “fitness” of growing media in the greenhouse. The amount of soluble salts is assessed by measuring the electrical conductivity (EC) of a mix. Watering practices have a dramatic effect on the levels of soluble salts in a growing medium. Salts originating from fertilizers or water provided to a crop can and will “build up” as leaching is reduced or eliminated. So a critical point to remember is that when growers reduce leaching for various reasons, especially with larger sized containers like hanging baskets, growers will most likely see higher EC levels. Invariably nothing has changed in the mix but the growing practice. Continue reading “Notes from North Central”