Healthy cannabis requires healthy soil, and fans swear by this mix.

Even with swanky dispensaries all over, some people still prefer to grow their own. This take on a time-tested recipe, originally published by the BC Growers Association, became well known in the underground cannabis world more than 30 years ago and has since become popular among home-growers and professionals alike. (Just remember California state law allows up to six plants, in a locked space out of view.)

Ingredients:

• 4 cubic feet of Promix soil, or a substitute without fertilizer and with sphagnum, perlite, coir, gypsum and mycorrhizae.
• 3 cubic feet of vermiculite, a mineral to help with drainage and water retention.
• 6 cups bone meal, for phosphorus.
• 2 cups blood meal, a nitrogen source.
• 1 cup Epsom salts.
• 3 cups dolomite lime to keep the pH level steady.
• 2 cups fish/seaweed emulsion.

Optional, but recommended, is a mycorrhizal inoculant – a beneficial fungi. The spore count should be above 60 per 50ml.

Directions:

Mix the ingredients thoroughly and moisten before use. To gain the full benefit of a living soil it’s best to wait one or two weeks to use.

This recipe makes about 52 gallons of soil; adjust based on how much you need. You can store extra in a garbage can with a lid and make sure it stays slightly moist.

The total cost for these ingredients, roughly $100, may seem high, but it comes out to about $1 per two-gallon pot – and fans say it will grow the best cannabis (or tomatoes or peppers or whatever you want out of your little plot of land).