Yes. If you really want to keep it simple, I would go to the hardware store or garden center and get 3 things:
- Bagged organic "potting mix" (one that has perlite already in it, brand does not matter)
- Bagged compost or worm castings (the higher quality the better, this is the one ingredient you don't want to skimp on)
- An organic dry fertilizer blend geared towards veggie gardening (Espoma brand products like Garden-tone, Plant-tone, Bio-tone, Tomato-tone, etc are readily available in the US. Any one of them will work, just get one and stick with it. I dunno about where you are located, but anything with a relatively balanced npk (each number between 3 and 6) that seems intended for vegetable gardening or is labeled "all-purpose"will work)
Mix together about 3-4 parts potting mix to 1 part compost/ewc. That's your base. Then for every 7.5 gallons (1 cubic foot) of base, add 2 cups of the dry fertilizer blend, and mix it in. So the ratio would be something like:
- 6 gallons potting mix
- 1.5 gallons compost or ewc
- 2 cups fertilizer blend
I don't think cooking is necessary with this recipe unless it gets warm (to the touch) within a few days of mixing, which I doubt it will. But if you do want to "cook" it, save some of the plain potting mix (before adding anything else) and use that to start your seeds in smaller containers. By the time they're ready to transplant, the mix will have had a few weeks to settle down.
Throughout the grow, top-dress every 3-4 weeks according to the directions on the fertilizer bag. Maybe mix some compost or worm castings in when you top-dress. Do the same during veg and flower, if you get a decent all-purpose fertilizer blend you shouldn't have to change it for the different stages of the plant's life.
I'd go with containers on the larger side. For autos, I'd go for 5-7 gallons minimum as their final pot. The bigger the pot, the more food the plants will have.
Sorry for the long read, hopefully that all makes sense. My point was, the above mix has only 3 "things" you need to buy in order to make it. A lot of soil recipes you see on weed growing sites will have at least double that, heck I've seen some recipes with 12-15 individual ingredients. That's fine for folks who really want to nerd out about different amendments, or have a really fine-tuned mix, but the dry fertilizer blends have all the same amendments (bone/blood meal, rock dusts, guanos, etc) in them already. So just buy a blend and add according to the directions on the bag. It may not be "ideal" or 100% exactly what the plant needs, but it's plenty close enough.
One big thing I've taken away from some more knowledgeable members on this site is, weed is just another flowering annual plant, probably like a lot of things in your mom's garden. It doesn't have any cannabis-specific needs, the same growing methods that work for tomatoes and peppers will work for weed. Good luck!
