Cornmeal is known as a natural substitute for chemical preemergent herbicides. Using cornmeal as weed killer is a great way to eradicate weeds without the threat of toxic chemicals. Learn more here. Also, a natural Ant Killer.
All you need is a small amount of vertical space around a balcony or an open window which can hang or store a vertical array of drink bottles that can grow all your herbs and lettuce easily. Recycle as many of your plastic drink containers.