Need education on "Dragon Fruit growing

In foreground two more of my dead immature dragon fruits this Summer. In background two more of my neighbor's ripe fully grown dragon fruits.

Mine was planted in a pot int the ground with extra holes in the pot with the hope that if we moved I could take plant with us. I am going to dig down & remove as much of the pot as possible and then do research on growing Pitaya Cactus. This one was bought for my oldest daughter because she likes the fruit so much.

Any suggestions from "blipfoto" or facebook people would be appreciated.