Tasty dragon fruit is easy to grow

If you have been to one of our farmers markets lately, you know that dragon fruit is in season. Yum. The several varieties of this tasty fruit are not hard to grow. Buy a few examples to taste and pick a favorite to grow.

All dragon fruits are in the Cactaceae family. Like other cactus, they have fleshy stems and sharp spines and do best in hot, dry climates. Of the 110 genera and 1650 species of Cactaceae, all but one are native to the America tropics. Though the exact native location of the dragon fruit species has never been resolved, the tropical jungles of Central America are the most likely origin. Europeans brought the fruit overseas from the Americas and began trading it in Asia. Today, the plants are cultivated in tropical countries including Thailand, Vietnam, Indonesia, Israel, northern Australia, southern China and the Philippines as well as in Hawaii.

Hylocereus undatus is the most cultivated species in this genus and is known by many names some of which refer to its night blooming habit. The common names include dragon fruit, pitahaya, night blooming cereus and belle of the night. The botanical name is a combination of the Greek word hyle meaning woody- matter and the Latin cereus, which translates to waxen. The Latin word undatus refers to the wavy edges of the stems. The genus is variable, however, and closely related to Selenicereus species, which are often called sour pitayas.

The sweet pitayas come in three types, all with leathery skin with spines. Hylocereus undatus (white-fleshed pitaya) has red-skinned fruit with white flesh. This is the most commonly seen dragon fruit. Hylocereus costaricensis (red-fleshed pitaya, also known as Hylocereus polyrhizus) produces a red-skinned fruit that has red flesh. Hylocereus megalanthus (yellow pitaya, also known as Selenicereus megalanthus) has yellow-skinned fruit with white flesh. Many find this variety to be the sweetest.

Dragon fruit can be grown as an ornamental plant, as well as a fruit crop. It is certainly a good choice for a xeriscape garden as it is very drought tolerant. An attractive sprawling or vining cactus, pitaya can grow as a terrestrial or epiphytic plant. It is often used in gardens as a flowering vine and it grows well indoors as a houseplant. The plant branches often and can fill an area completely if left unchecked. It climbs by using its aerial roots, sometimes reaching a height of 30 feet or more growing on rocks or tall trees. The vines do best with the support of a trellis, ladder, umbellate structure, wall or other large plants.

All members of the genus Hylocereus have fleshy, waxy green stems that are usually three sided and segmented with short spines along the wavy edges. In the absence of leaves, the stems perform the photosynthetic process that provides energy for the plant. The thick waxy stem surface reduces transpiration, saving water. They are also good for reflecting harsh sunlight and providing a thermal layer to protect against temperature extremes. The spines offer defense as well as water trapping help by collecting dew.

The large, white, fragrant flowers of the pitaya bloom at night off nodes directly on the stem, relying on nocturnal pollinators including moths and bats. Each flower usually wilts by morning. Heathy plants can flower up to six times a year depending on the growing conditions. Several species do not self-fertilize and will not produce fruit unless hand pollinated. This presents a challenge to home growers wanting to grow the fruit.

With pollination, fruit will form at the base of the wilted flower. Once formed, it can ripen in five to six weeks. The fruit is oblong to oval and can be as long as 6 inches and 2 to 4 inches thick when fully mature. The exterior can be red or yellow with large, soft bracteoles like those below flowers. The pulp is sweet and either white or red containing tiny, black, edible seeds. The edible interior is soft and moist with a delicate aroma and taste. Large, healthy fruit can weigh up to 2 pounds.

Like some other cacti, a healthy piece of the stem can develop roots at its nodes and be planted in soil to become a new plant. Commercial plantings are often located in full sun though the plants can also do well in partial shade. Hot and sunny locations with light watering are best, but dragon fruit can grow well where rain is heavy, as long as the soil drains well.

There is a locally famous quarter mile hedge of Hylocereus undatus growing on a lava rock wall at the Punahou School in Honolulu. The hedge was planted by a Mrs. Bingham in 1836. Its exotic blossoms still bloom from July to as late as October creating a wall of sweet smelling white flowers. Supposedly, most of the H. undatus in Hawaii came from this wall. People used to come in the evenings from all over to see them in bloom and “borrow” cuttings, thus spreading the species.

Though plants can be propagated from seed, growing from cuttings is probably easier. Cuttings will often start to sprout roots without water, soil or hormones. Plant cuttings about 1inch deep in good potting soil and water only once every two weeks, letting the soil dry out between waterings. In filtered sunlight and warm temperature, the vines roots will continue to grow. Once the roots are established, new vines will sprout from the stem’s nodes.

To grow from seeds you need to first extract the seeds from the flesh. To do so, mash up a teaspoonful of the flesh in a little water and separate the seeds from the pulp. Remove as much of the pulp as possible and either sow the seeds in a potting mix or dry them to save for later planting. Water and cover the container or wrap it in a plastic bag. The two seeds leaves should appear in a couple of weeks. These are the first and last leaves that this cactus will produce.

As the seedlings develop, an angular spiny succulent stem grows in the central growing point between the two leaves. The stem thickens and elongates and after several months the seed leaves shrivel and fall off. At this point, the seedlings can be potted into individual pots for further development before placement into the landscape.

Though dragon fruit can be grown in any soil that drains well, a mix of topsoil, cinder and compost will give your plants a good start. Though moving them can be tricky, wrapping the thorny stems in a roll of newspaper can help protect your hands. Good rich soil and extra sunlight in the early spring will stimulate budding and flowering. Fertilizers with phosphorus and potassium applied in the spring will also aid in flower production. Applying nitrogen fertilizers in late fall and winter will keep the stems from yellowing.

Pitaya is subject to few diseases or pests. Birds do love the fruit and can be a problem once they discover it. Extended overwatering can cause the flowers may drop or the fruit to split or rot. Stem rot can also be a problem when plants are over watered or during periods of excessive rain. For more information on growing dragon fruit in Hawaii, check out the University of Hawaii College of Tropical Agriculture and Human Resources publication at http://www.ctahr.hawaii.edu/oc/freepubs/pdf/F_N-9.pdf.

Call around to area nurseries for dragon fruit plants. Tropical Edibles Nursery in Captain Cook often has them. You may also be able to get cuttings from farmers who are growing and selling dragon fruit at one of farmers markets. In any case, with dry weather on the way, we think, consider this drought tolerant fruiting plant with the gloriously fragrant flower for your garden.

Diana Duff is an organic farmer, plant adviser and consultant.