Spread a 2- to 3-inch layer of mulch over the soil and around the base of the dragon fruit plant in late fall as temperatures begin to cool. Leave a space between the cactus stem and the mulch layer so they do not touch. The mulch helps insulate the soil and protects the roots from mild frosts.
Water the dragon fruit throughout winter when the soil begins to dry but only when temperatures are above freezing. Stop irrigation in spring once the temperatures begin to warm, as lack of water forces the dragon fruit to bloom.
Erect a wind barrier on the windy side of the dragon fruit in areas with strong winter winds. Cold winds can dry out the plant or cause freeze damage. Stretch a length of burlap between two stakes to make a quick barrier.