To grow dragon fruit, you will need to plant two of the dragon fruit cacti to allow cross-pollination. Blooms appear several times a year, producing successive crops. The flowers open for one night only and are pollinated by nocturnal bats or moths. The exotic dragon fruit cactus grows from a single trunk, about 4 feet tall, then branches into sprawling limbs that produce up to 220 lbs. of fruit per year according to the University of Florida Extension Service. The branches are long and heavy and require support to keep them off the ground.
Dig a hole three to four times the size of the cactus root ball using a shovel. Select a location that is sunny and well-drained. Moisten the soil and amend it with 4 to 5 lbs. of organic material.
Place the dragon fruit cactus in the hole at the same level it grows in the pot. Backfill with soil and tamp it down firmly.
Water deeply after planting and as needed during dry weather. Let the soil dry out between watering, then water thoroughly. Cover the ground with 3 to 6 inches of organic mulch to conserve moisture and discourage weeds.
Begin fertilizing one month after planting. Fertilize every other month with a general balanced fertilizer such as 10-10-10. Apply a nutritional spray every one to two months between March and September.
Provide a strong, T-shaped support or a large pile of rocks to support the sprawling cactus. The branches on a mature dragon fruit cactus weigh several hundred pounds; make sure your support will not fail under the weight. Loosely tie the main trunk and branches to the trellis. If wires are used, they must be covered with hose to avoid cutting the plant.
Erect a shade cloth to protect the dragon fruit cactus from sunburn during the first few months.
Cut away side branches with clean pruning shears until the trunk reaches the top of the trellis. Then, cut off the tip of the trunk to encourage branching.
Remove dead and damaged branches as they occur. Prune the cactus several times a year to keep the branches off the ground and control the size.
Remove all cuttings from the garden and compost them. Even a small piece of cactus left behind can quickly root and form a new plant, quickly taking over the garden. Be careful to avoid nicking the plant when lawn mowing or doing gardening tasks.
Allow the fruit to stay on the plant for 30 to 50 days after they first appear. They are ready in 30 days but will continue to grow and get sweeter for another 20 days.