The easiest way to propagate dragon fruit plants is by cuttings. They can also be grown from seed. Take cuttings when the plant is growing actively. Seeds can be started any time indoors. The cactus is damaged by freezing weather.
Take cuttings from a branch that is over a year old. Cut the branch off where it joins the main stem or meets up with year-old tissue. Place the cutting in a shady place for several days to allow a callus to develop on the cut end. Then put the cutting in cactus potting soil, cut end down. Roots should form in a few weeks.
Remove a ripe fruit from the dragon fruit tree and separate the seeds from the pulp. Wash the seeds clean using a tea strainer. Lay the wet seeds out on paper towels to dry. Plant the prepared seeds in cactus soil, barely covering them. Keep the container moist and partially cover it with plastic film or a pane of glass. Uncover the container when seedlings are 1 inch tall.