Hylocereus undatus

The Hylocereus undatus, now renamed Selenicereus undatus, is a species of cactus better known by its fruit, the pitaya or dragon fruit. This tropical plant behaves like a climbing plant: rooted in the soil, it needs support to grow. In its natural state, it forms very long segments with few thorns, reaching several metres long. The very large white flowers that bloom at night produce after fertilisation pinkish-fuchsia fruits with highly ornamental scales and a subtle flavour. In our climates, this cactus will be cultivated in a pot and brought indoors to a bright and heated shelter at 10°C during winter. A plant for passionate enthusiasts!

Hylocereus is one of the 90 genera that make up the Cactaceae family, which is rich in about 2500 species, primarily American. This group of plants is very diverse, including arborescent or columnar plants, globular or prickly pear-shaped (Opuntia), epiphytes (which grow on other plants like trees), and even a few climbers, such as the genus Hylocereus. The latter includes 20 species native to Mexico and other countries in Central America. Originally from the Yucatan Peninsula (Mexico), the Hylocereus undatus is also found in several countries in Central America. Since the success of its fruit in international markets, it has been widely cultivated for food purposes, especially in Southeast Asia.
This curious cactus is not an epiphyte as its roots in the soil, but lacking sufficient rigidity, it needs support to rise, making it a true climbing plant. In its native lands, it develops very long stems, which can exceed 6 metres in length. Green in colour, their cross-section has three wings with undulating edges along their entire length. The areoles (small typical protrusions of Cactaceae) are widely spaced and usually have only one mildly aggressive spine. The plant produces aerial roots, which help it climb on its support. In commercial plantations, the cactus is fixed to a nearly 2-metre-high stake, from which it falls on both sides, eventually resembling a mini palm tree due to its easy branching.
In the tropics, the mature Hylocereus (after about 12 to 15 months) can flower and bear fruit 4 to 6 times a year. In temperate climates, annual flowering usually occurs from June onwards. The flowers are white, bell-shaped, very large, measuring up to 35 cm long and 25 cm in diameter. Highly ornamental, they open at dusk and bloom during the night, spreading a vanilla scent in the air. In the tropics, they are pollinated by bats that help spread the pollen from one plant to another, as a plant cannot fertilise itself. If you want to venture into fruit production, you will need at least two plants and take care of pollination during the night! In tropical climates, it takes approximately 30 days for the fruit to reach the harvesting stage, with the scales still green. Oval in shape, the fruit can weigh up to 700 grams and has a pinkish-fuchsia colour, beautifully contrasting with the green and then yellow scales. This form has white flesh dotted with tiny black seeds and varieties with red or purple flesh. Highly decorative, it is also edible and appreciated, with a sweet taste that is not excessive, suitable for all palates.

The Hylocereus undatus is an original plant that will attract true enthusiasts who have a suitable space to overwinter it, such as a greenhouse or conservatory with minimal heating. It cannot be planted outdoors anywhere in Europe, which limits its distribution. Fans of exotic plants can grow it in a large container and provide it with a stake to climb. It can be accompanied by orangery species, such as the astonishing Buddha's Hand (Citrus medica var. sarcodactylis), a Citron tree with long finger-like fruits and a highly aromatic zest. The true Lemongrass (Cymbopogon citratus), a tropical grass whose leaves are used in many Asian dishes, is just as easy to grow in a pot to bring indoors during winter. 

The pitaya has acquired real economic importance. In 2023, this fruit generated a total revenue of over 14 billion dollars (US). Vietnam is the leading producer, accounting for about 50% of the global volume on a cultivated area of 55,000 hectares. The variety with white flesh represents 95% of the production, and Europe is the market with the highest current growth.