Steps to becoming a vigilante gardener:
1. Identify abandoned reality TV house.
2. Look for signs of an herb garden producers probably planted thinking the cast would care about sustainability. Preferably on public property, i.e., the sidewalk. See anything you think you might not kill if you transplanted it to a pot in your kitchen?
3. Double check that you're not going to uproot a perfectly good plant only to slaughter it brutally in captivity.
3a. Hmm, Wikipedia says that rosemary does well in drought conditions. The top of my refrigerator gets very little rain, so this is excellent news.
4. Liberate your target plant from its sidewalk home. Preferably under cover of darkness, even if it is on public property.
4a. You probably shouldn't remove the all the rosemary--that's a little greedy. And, furthermore, you're going to feel like an asshole if you kill all of it in one fell swoop. You have to pace yourself.
4b. You probably didn't plan this exercise very carefully, so chances are you lack an appropriate vehicle in which to transport your rosemary plant to its new home. Fortunately, since you're not a greedy asshole, you can carry it in one hand.
5. Pot your exciting new plant. You might have an enormous bag of potting soil living on your fire escape, an artifact of your last foray into the wonderful world of herb gardens. Seriously-- you might have carried a 20-pound bag of potting soil four blocks from Garden District and up two flights of stairs, because you might struggle with gardening, but you try hard and you appreciate economies of scale.
5a. You might also have some concerns about that potting soil and blame it for the stunted growth and eventual death of your basil plant. Maybe. I'm just saying. If that's the case, maybe you pick up a fistful of dirt from the garden in front of your building.
6. Enjoy your new plant. Remember not to over-water it, in the manner you over-water the Christmas cactus you keep at your desk hoping to reenact Little Shop of Horrors.