Home made worm castings, dissolve in water, job done! nuff sed! Agro-chemical grown weed will wreck yer lungs, fertiliser residue inevitably builds up in the plant fibres and if yer young and healthy, not much problem, if yer old, craggy, bin smokin every day fer 35yrs, it will kill you, slowly! I don't use any 'fertiliser' or pesticides, my bud is renowned as 'best in the manor' and despite my fragile asthmatic chest, I can smoke it till the cows come home with no adverse effects, 2 days on 'gangsta grown weed' leaves me a respiratory cripple, gasping for my first breath in the mornin.
Just this old fool's 'ha'pence worth'