You could use the way he grows to express some of the characters personality. Different types of growers would give the audience different impressions. It's a very different person that grows using an elaborate hydroponic system, with pumps, resovoirs, ph meters, and complicated chemcial nutrient programs than one that grows in an organic soil, keeps a worm compost bin, collects rain water, and fights pest with lady bugs. Whatever fits your character better. Advanced growing techniques to maximize yield include training a plant to grow horizontally to help the light reach more of the plant (LST, scrog,) or cutting off parts of the plant to increase growth elsewhere (topping,FIM, mainlining, lollipop) and then theres the SOG method which can be used to continually harvest plants. Search any of these terms and you'll find plenty of info on them.