Never rely on anything you buy prepackaged, like soil although obviously a lot of quality products exist. Yes you will need to add nutrients. If indoor fuck the soil of and use coca husk and sand or perlite. If outside first get a big fucking pot and paint it green for cammo reasons, Get a soil mix and split it with something airy and sandy like prelite or vermiculite, and add a hand full of slow release pellets. If your already in the ground or potted well you have to hope you have a decent soil mix. Using blood and bone, both liquid and wet is excellent but attracts the wildlife, Worm castings excellent, liquid dynamic lifter excellent, seaweed extracts excellent, i have always found dry fertillisers that are chemicals mixed in water to be mediocre. Liquid poor on stuff is good but not on the leaves, if it smells like your dead grandmother, excellent. Dont over do it better to make a mix a little weak at first and watch for results wich you will see in a day or two and increase in potency, and let the fuckers dry out every couple of days as this forces the roots to grow and look for water thus giving a bigger plant. hope that helps. Also if digging a patch outdoors, work the soil with sand, dig a pit close to a foot deep and throw into dead bait fish, yummy!