Soilless Potting Media
When talking about container gardening, often you will hear the term “soilless” when referring to different types of media. This term is often confused with soil, which sometimes might not be sufficient for certain types of container gardening.
Advantages of Soilless Media
Garden soil comes with two major disadvantages in comparison to soilless media. To start, garden soil comes with many unknowns, including diseases, bacteria, insects and weeds. Outside, there are many natural predators and environmental to keep these things in check. If you are using garden soil indoors, be sure to sterilize it first.
Secondly, many native garden soils are devoid of necessary aeration amendments needed to successfully garden in containers. Without tilling, either by man, worms or other insects, garden soils can easily become compacted within a few watering’s. This is especially harmful to plants with delicate root systems, including seedlings.
Another benefit of using soilless media is that it is easy to fertilize. Whether using bottled nutrients or organic amendments, soilless media provides the necessary holding capacity and drainage to meet all feeding needs.
Ingredients of Soilless Mixes
There are many different components of soilless media, the most prominent being peat moss. It’s light, but its fibrous structure allows it to hold 15 to 20 times its weight in water. The peat fibers also give it a large amount of pore space (up to90 percent of its total volume). It holds and share nutrients readily with roots. The number one issue with peat is that it is NOT a renewable resource. A common substitute that IS renewable is coir.
Coconut coir is a renewable resource derived from the husks of harvested coconuts. Coir has exceptional water-holding capacity, and when mixed with aeration amendments, it can eliminate or substantially reduce the need for peat moss in a mix.
The most popular aeration amendments are vermiculite and perlite. Vermiculite is a heat expanded mineral, and holds high amounts of both air and water. Perlite is heat expanded volcanic material that creates a small, lightweight, white particle. It provides excellent drainage while holding nearly as much water as vermiculite.
Many products on the market today contain around 40% peat/coir and 60% aeration amendments. Popular soilless media products on the market today include Pro Mix, Royal Gold Tupur, and Sunshine Mix.