Seed saving for After Pole Shift times

An idea to get us able to recognize plants and seeds and to start saving I have a recommendation and a challenge for those in the city.  

Keep some plastic bags and small clippers in the car. While driving around keep your eye open for vacant lots where weeds grow. Become familiar with weeds and herbs that are edible.  

When you see something that has gone to seed harvest as much as you can.  These will be non-hybrid and able to grow in the type soil you have.  Do this harvesting of seeds in and around your yard also.  Do it for all plants you like.  After the PS you can place some outside at random to see if they grow from time to time.  Some items will not be efficient for us to grow indoors but if started outside maybe in 20-30 years when the toxicity of the environment decreases it will have populated the area for you and be safe to eat.