I used to spend $300 per grow just on nutrients, then I learned about organics, and now I feel really stupid for falling into the cannabis nutrient marketing. The first thing I did to reduce cost was compare a bunch of different soils. I tested Roots Organic, Fox Farm Ocean Forest, Miracle Grow Organic, Super Soil (made by Scotts, not Sub), Earth Gro, Kellogg Patio Plus, Mushroom Compost, Coir, Me's Mix, Promix, Sunshine #4, and a few other local potting soil brands and blends that I made up myself (like peat + worm castings, coir + castings, etc).
In my opinion Roots Organic was the best, but it was also the most expensive at $30 a bag. The second best performing potting soil was Kellogg Patio Plus at $4 a bag. The rest did pretty good, except for Promix that I picked up at Walgreens. I didn't like the promix at all. Also, by harvest, the between Roots Organic and Kellogg Patio Plus wasn't really that big and often times the weather and strain had more to do with growth than the soil. Although Roots Organic did have coc coir which I love, so water didn't drain as fast, and it was broken up in smaller chucks, so it felt lighter and fluffier. However, Kellogg Patio Plus was ORMI certified organic, had guano, castings, mushroom compost, and tons of beneficial organisms. The only thing I didn't care about the Kellogg Patio Plus was the bark. I wish it would have been cut up more to make it more fluffy, but in the end it didn't seem to matter much.
I've done grows directly in the dirt (and amending the soil based on the results of a soil test) and I've also grown in containers as well as in raised beds. Between all three methods, I've found raised beds 6" to 12" deep and placed directly on the ground did the best. The roots are able to go past the raised bed's bottom, so you get all the benefits of planting directly in the ground, but you don't have to dig, or amend the soil in anyway because the first 6" provides all the nutrients. Right now I even have some really large Sativas growing in pure Kellogg Patio Plus potting soil that I started back in march. i haven't needed to fertilizer yet and it's almost September. To me, that speaks volumes.
As for nutrients, I like Alaska Fish Emultions (5-1-1) paired with Alaska MorBloom (0-10-10), however being that fish have heavy metals (like many synthetic fertilizers) I decided to stop using them. It also disappointed me that Alaska MorBloom is no longer certified organic. It used to be several years ago, so I don't know if they changed formulas or if they simply stopped paying for ORMI certification. I also tried a bunch of different synthetic hydroponic nutrients (from Advanced Nutrients to GH and even Veg+Bloom), but I've always hated the weekly feedings, the constant ph adjusting, and the need to "dial it in." After joining my local community garden, I learned from people who were growing roses, corn, tulips, and so many other types of flowers that they all really liked Kellogg's fertilizers because they were cheap. Now these people never heard of the hydroponic stuff and they didn't grow cannabis, but they did know how to grow. It also didn't hurt that I already loved the Patio Plus potting soil, so when I seen that Kellogg made a fertilizer at $8 for a 4 lb bag, I went for it, and quickly fell in love with it.
At first, I wasn't sure which version of Kellogg Fertilizer to use so I tried their version for tomatoes, flowers, and their all purpose mix. It took me about three years to figure out that the all purpose one was the best one for me. I only have to apply it 2-3 times a year and it works really good. It has kelp meal, feather meal, bone meal, alfalfa meal, humic acid, mycros, and tons of other goodies that i wanted in a fertilizer. When you pair this with the soil you now have worm castings, guano, and mushroom compost. I also love that I don't need to add cal/mg or lime. It works as-is without anything extra and I can use unfiltered water which when I measured it, had a pH of 8.0 to 8.1.
To fill a 3'x'3x6" raised bed with Kellogg Patio Plus it cost me around $30, then figure another $8-$10 for fertilizer, another $6-$8 for wood to build the raised bed, and IDK how much for water, but it's not much especially that I've recently upgraded to a soaker hose and a timer.
The only other things that I would add is Miracle Grow Water Storing Crystals and maybe include a budget for Diatomaceous Earth ($10), Yucca Extract ($8; use in place of dish soap), horticultural oil like neem or sesame oil ($10-$20), and an organic insecticidal soap like Safer 3-in-1 or Rose Rx ($6-$10).
