Face it, if you're eating canned foods and rice and beans for survival, you're going to need some fresh vegetation.  A diet without roughage can cause health issues, and that's the last thing you need in a survival situation.  Having vitamin-packed greens growing regularly in your home, is the solution.  Learn how to grow veggies that have 4x more nutrient density than a piece of broccoli, ounce for ounce.