There are lots of choices when it come to filling your garden beds or grow pots with a potting blend or soilless mix-but it doesn’t have to be complicated or terribly expensive with easy potting and grow mix blend recipes.
Store bought potting soils-not to sound “down” on anything-like the ones from the hardware or grocery store are not likely the best choice if you are looking for a more productive garden with bountiful yields of great quality harvests.
They tend to be more “heavy” and are typically not sterile, or maybe not even intended for bringing indoors. Composts in a hot grow room are not only offensive, they can be downright unhealthy.
For example, a grower may prefer more water retention and add more of other ingredients and less of others in the base ratio to achieve the right consistency for their watering and cropping requirements.
Other growers may prefer to feed less often, so they may choose to add amendments to boost soil fertility throughout the growing seasons. These may be added directly into the mix or lightly worked in through the growing season in fast acting, intermediate and slow release forms.
Soil acidity or pH is also a consideration. As a basic rule, the more peat moss or organic matter you add (or plan to add through fertigation and waterings) the more you will need to buffer against acidifcation of the soil that can lock out nutrients, resulting in poor growth.
A mix of hydrated lime and dolomite lime in prilled form is cheap to add, usually half a cup of each per bale of commercial peat moss planting mix or a full cup (250 ml each) of each to straight large size bales of compressed sphagnum peat moss will do the job for an average 2-4 month span in the planting mix.
Some growers will also add a few handfulls of Epsom Salts per bale of spahgnum peat mix too.
Using coconut coir as a base in your growing mix is also very productive. In some areas it may also be more economical and is a more environmentally sustainable media, in respects, versus shagnum moss. WITH COCONUT COIR IT IS NOT ADVISED TO ADD ANY LIME, RATHER, PRE-TREAT WITH A HYDROPONIC CAL-MAG SOLUTION.
Many growers like to use about 1/3 coconut coir to commercial peat mix as a portion in their base mix for potting and grow mix blends.
Below is an Easy Potting and Grow Mix Blend Recipe and uses the following ingredients and ratios. It can be modified any number of ways as mentioned above and also with aerobic compost tea or beneficial microbial inoculations to improve plant vitality and nutrient cycling. Vermiculite may also be commonly added at about 1/4 ratio to that of perlite (below) to provide some water retention and CEC (cation exchange capacity) for buffering fertilizers.
30 L OMRI Certified Earth Worm Castings
107 L Professional High Porosity Peat Moss Soilless Mix
30-40 L Large Diameter Horticultural Grade Perlite (wet down before emptying or scooping)
125 ml hydrated lime
125 ml prilled dolomite lime
This is enough mix for the needs of 1KW for indoor gardening in containers or about a square meter of medium depth planting bed.
Experiment, but it’s best to try on just a few containers or sections at a time following this recipe as your standard or baseline for healthy growth and production in conjunction with a good quality crop feeding program.
Erik Biksa has been writing about and discussing hydroponics growing, related technologies and cropping methods since 1999 in a variety of professional publications and platforms globally Erik has travelled the world learning and teaching modern growing techniques and technologies and is appreciated by many growers for his informative yet hands on approaches. Presently, he is the Editor at Grozine Hydroponics Mag.