I grew these red dragon fruit plants from seed last winter. According to seed descriptions dragon fruit grow “rapidly” from seed. I don’t know if rapid is quite the right word, but they are doing well for me, continuing to grow during the winter when most plants are dormant.
They have lived inside for most of their lives so this is their first time growing outside. They seem to be enjoying it, although a teeny bit sunburned from the shocking brightness.
I read somewhere that dragon fruit plants won’t fruit until there is at least 10lbs of plant mass. Oy. I don’t even want to know how long that will be. I’m just guessing, but these cannot weight more than a couple ounces each.
The base of grafted cacti (the green part) is actually a dragon fruit cutting with another type of cactus mounted on top of it. If you remove the colorful ball-shaped cactus, the green part will continue to grow and branch, etc. It may be possible to grow a larger plant more quickly from a cutting that has a significant diameter. I have not tried this method, but it would be interesting to compare.