There are strict rules against "dumpster diving" but when I was young and we bought a house but couldn't afford to buy landscaping stuff, I would periodically check the dumpsters at Kmart and when they would throw away "old" bedding plants, I would "dive in" on the sly and pull them out. Planted many a flower bed doing that over the years. Maybe someone would have to inventory and account for where all the stuff went that they get rid of and no one wants to take on what would probably be a monster responsibility?