Around 1542, when the phrase first appeared, "to go to pot" was to be cut up like chunks of meat destined for the stew pot. Such a stew was usually the last stop for the remnants of a once substantial cut of meat or poultry, so "going to pot" made perfect sense as a metaphor for anything, from a national economy to a marriage, that had seen better days. Early uses of the metaphor were usually in the form "go to the pot."

1) "go to pot to be damaged or spoilt because of a lack of care or effort. My diet has gone to pot since the holidays. " Source: http://idioms.thefreedictionary.com/going+to+pot 2) " Around 1542, when the phrase first appeared, "to go to pot" was to be cut up like chunks of meat destined for the stew pot. Such a stew was usually the last stop for the remnants of a once substantial cut of meat or poultry, so "going to pot" made perfect sense as a metaphor for anything, from a national economy to a marriage, that had seen better days. Early uses of the metaphor were usually in the form "go to the pot." Pot: To take pot luck is to be offered a choice from what's available and not from what you might wish. It goes back to the days when a cooking pot was always on the fire. An unexpected guest was welcome to eat but only from what was on offer in the pot. To take a pot shot has the same basis - to shoot at game in general in order to get something for the pot rather shooting at a specific type of animal. If someone has gone to pot then they are thought to have deteriorated or declined from their previous status. The pot here is the melting pot into which valuable pieces of stolen silver and gold were remelted. They had gone to pot never to re-appear again. In spite of this probable origin, it is quite possible to relate the saying to the cooking pot described above. Who knows?" Source: http://www.phrases.org.uk/bulletin_board/5/messages/1224.html 3) "Dear Word Detective: On a recent trip to Turkey we were visiting an ancient ruin where people were buried in large "pots." When the next family member died we were told that they would be put in the same pot. Does this have any relation to our expression "going to pot"? -- Edie, via the internet. I knew there was a reason why I never visited Turkey. But, of course, I mustn't presume to judge the burial traditions of another culture. After all, my own youth was spent tending to an informal pet cemetery in our suburban backyard, where row after row of goldfish, turtles, hamsters and the occasional unlucky sparrow were interred with all due solemnity. To this day I cannot bring myself to throw away shoeboxes and similar small-animal-sized containers, although I do keep them in the basement so as not to unnecessarily upset the current menagerie. All my little clients had "gone to pot" in the figurative sense meaning "deteriorated or destroyed," but I would never have dreamt of them "going to pot" in the original sense of the term. Around 1542, when the phrase first appeared, "to go to pot" was to be cut up like chunks of meat destined for the stew pot. Such a stew was usually the last stop for the remnants of a once substantial cut of meat or poultry, so "going to pot" made perfect sense as a metaphor for anything, from a national economy to a marriage, that had seen better days. Early uses of the metaphor were usually in the form "go to the pot." Speaking of stew, it's a tribute to the enduring popularity of this combination of boiled vegetables and meat that almost every culture in the world has developed its own local version, from Hungarian goulash to Scottish "hotch potch" (whence our "hodgepodge," meaning "jumbled mixture"). We also still speak of someone slowly boiling with anger as being "in a stew," and, if we decide to ignore him, he "stews in his own juices."" Source: http://www.word-detective.com/012199.html 4) "gone to pot - Time eventually wears everything down. For example, once great downtown department stores declined, went to pot and were replaced by suburban malls. If you've ever gone to a high school reunion, you know how just a few years, a few pounds, and a few gray hairs can make old classmates look like they've gone to pot, too. But why the pot? Is something cooking? Whatever counter-culture references the phrase may bring to mind, it actually is about the kitchen. In the Middle Ages, table scraps ended up in a big pot for stew. Once the centerpiece of a big meal, main courses were demoted to leftovers. Eventually "going to pot", meaning going downhill, would be applied to anything, even the guy who sat behind you in homeroom years ago. Source: BREWER'S DICTIONARY OF PHRASE AND FABLE" Source: http://www.obcgs.com/sayings.htm