Dragon fruit are pretty easy to grow. All i did was just stick a cutting in the ground and in less than a year it has grown more than 7 feet tall. From one original plant i took cuttings and i have 3 of them growing up on a piece of wood and they are each over 7 feet tall. It hasnt produced fruit yet but hopefully it will this year cause they are pretty big now.

They are easy to grow, but slugs love them and they can get rotten spots on them from too much rain, an issue in our Puna location also. Some people grow them in greenhouses here.