The smell from plants only really gets noticeable once your in flowering - and even then it'll be a faint smell. The only way you'll have a plant STINKING is if you [or maybe a fan if your growing inside] moves the plant which in turn breaks some trichomes. They are what realeases the smell. The stems stink too if you touch them. But as all growers know, you shouldnt touch the trichomes, and therefore you should make much of a smell. Although some strains do smell more than others - and some smell so fruity you wouldnt actually know it's cannabis, apart from the looks.