Growing vegetables from food waste is a great lesson for kids and also makes great science experiments Teach students how to regrow food and pick a food to regrow as a class. Could use a food from a students leftover lunch.
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.
All in one organic fertilizer + pesticide. The world's most perfect fertilizer + pesticide is epsom salt. every other week- 1 gallon of water, 1 TBSP of miracle grow and 3 TBSP of epsom salt- I promise a great garden all season.