Growing Media for Greenhouse Crops
Grower-Mixed Media versus Commercial Media
Greenhouse growers have the option of either mixing their own media or purchasing a commercially-formulated media. Growers who mix their own growing media have both control and flexibility: control over the selection of ingredients and the quality of the final product, and flexibility to choose from many media recipes tailored to specific crops, container types, etc. Growers who purchase commercially-formulated media, although more expensive, do not need to invest in mixing equipment and have the added flexibility in purchasing from suppliers who offer a diversity of media mixes.
Commercial Media
Premixed media is a common sight in the greenhouse industry. Suppliers offer a diversity of mixes in either pre-packed (bags, bales, super sacks) or bulk forms. Some mixes are prefilled into cell packs, seed trays, or pots that are ready to be planted. Recipes are specially formulated for propagation, specific crops, or general crops. Most commercial growing mixes have a nutrient charge that is balanced for starting plant growth. Some soilless proprietary mixes are very sophisticated, containing peat moss, vermiculite, and perlite, plus a nutrient charge of nitrogen, potassium, phosphorus, dolomitic limestone, micronutrients, and a wetting agent with the pH adjusted to about 6.5.
Grower-Mixed Media
The decision to mix one’s own media, as opposed to purchasing commercially-formulated media, is basically an economic one. Growers can typically save 25 to 45 percent in material costs by mixing their own media. Costs include mixing equipment, raw materials, skilled labor, and quality control testing. Not only the cost savings, but the inherent flexibility to produce any mix formula as needed is usually another reason why growers mix their own media.
Advantages of Soilless Mixes
Soilless mixes offer several advantages over a conventional soil mix.
