mix 1 bag of organic garden soil, 1 bag of organic potting soil, 1/4 bag perlite ( add more as needed ), 1 small bag organic fertilizer ( read the mix ratio). Put it all in doubled 55 gal construction bag, ( split into two bags if necessary based on amount mixing) Tie off opening and roll around gently on lawn/ground for a complete mix put into your grow bags and you're ready. Anything you buy make sure it is dry to keep away the fungus nats. Research all soils before you settle. (Educational) Research and purchase organic "liquid" fertilizer Follow directions. And the most important as much as many may disagree, is PH your water to 6.5 to lesson any problems. Just my thoughts. Good luck. Good Growing !!