(That DOES sound cool.) Sometimes, your Sims autonomously decide to give the leaves a nibble. You don't have joints in your inventory, nor do you cultivate the plant, however.
If it's the latter, that's obviously their call.) With the PC Sims one, you just stick the plants anywhere and they grow (it's in Decorative/Plants). I did submit it, but either the e-mail got buried or the mods there decided not to use the submission. One is from Pandora Sims, one is from Blackypanther and one is an old cannabis plant I have from PC Sims. As far as I know, there are three hemp/marijuana/cannabis-type mods.