Greg says... Hi guys,
I have about 7 Dragon fruits growing now. They are an under story tree, so they prefer filtered light. There favorite thing to do is to climb up a large tree. They have a very shallow root system, and grow air-roots as they get bigger. They do not need much fertilizer or water, too much of either of these can cause problems. I am training mine over a trellis, and they are approx 3m high now. They take 2-3 years to fruit, so I still have a couple of years to go.