Outdoor soil mixes that incorporate garden soil, compost, manure, coco peat, and rock powders grow some of the best cannabis plants in the world. These mixes can be mixed a few months early and left in the hole to blend and mature. Outdoor organic soil mixes are alive, and controlling the soil life is a matter of paying attention to a few details.
Indoors, outdoor soil mixes often create more trouble than they are worth. Too often misguided novices go out to the backyard and dig up some good-looking dirt that drains poorly and retains water and air unevenly. The problems are compounded when they mix the dirt with garden compost packed with harmful microorganisms and pests. Such growers create unforeseen problems and pay for their savings many times over with low-harvest yields. Avert problems by purchasing all of the components.
Use garden soil or compost only if they are top quality and devoid of harmful pests and diseases. Use only the richest, darkest garden soil with a good texture. Amend the soil by up to 80 percent to improve water retention and drainage. Even a soil that drains well in the outdoor garden needs amending to drain properly indoors. Check the pH of the garden soil before digging to ensure it is between 6.0 and 7.0. Add fine dolomite to stabilize and buffer pH. Check pH several times after mixing to ensure it is stable.
Solarize garden soil by putting it out in the sun in a plastic bag for a few weeks. Turn the bag occasionally to heat it up on all sides. Make sure the bag receives full sun and heats up to at least 140 degrees Fahrenheit. This will kill the bad stuff and let the beneficial bacteria live.
You can also sterilize soil by laying it out on a Pyrex plate and baking it at 160 degrees Fahrenheit for 10 minutes. It is much easier and more profitable in the end to purchase food potting soil at a nursery.