What I do is I oil my scalp with JBCO (Jamaican black castor oil) ever night and I've seen a big improvement. My edges and hair is much longer. You should try it.
I want my hair to grow what's the best routine for my hair to be healthy and for it to grow as well?
i use castor oil as well and it works :)
Most people love JBCO, so try that, but to practice overall hair health, I'd watch this video. Basically, keep it moisturized, take some hair vitamins, get frequent trims, cut off single strand knots or split ends, and eat healthy foods. :)