We had the most amazing vegetable garden once on a sunny three by six
foot balcony. We had rather little money, so we used leaf mold in
5-gallon buckets from the bakery and trashbag-lined boxes and fruit
crates. We had peppers, melons, lettuce, radishes, carrots, cukes,
zucchini, and tomatoes in remarkable quantity. If you don't have a
balcony, a sunny window might work, but you'd have to pollinate
fruiting vegetables with a paintbrush.