No garden and no containers? Doesn't matter. Just use humus sack, make holes in it and plant your vegetables. This is an example of tomato growing, but horizontally placed sack can be used for almost anything. Plant there cabbage, kale, chili, beans, potato.
If placed vertically, sacks can be used for growing lettuce making small holes all around, or for growing strawberries. Just keep the distance between plants as you would do usually, giving them enough space to grow properly.
Photos by knottyolly