Another version on rain gutter gardening. Want to grow a salad garden but have no room? Try gutters! Affix them to a fence, slope them for drainage, and voila! Of course,for this I'd need a backyard wider than a hallway.
Plant seedlings in lemon rinds for a different type of biodegradable pot. You can add a hole in the bottom of the lemon so that it drains properly. This DIY gardening trick can save you both money and time.