Hylocereus megalanthus - Yellow Pitahaya

The Pitaya or Yellow Dragon Fruit, known by its Latin name Hylocereus megalanthus, is an epiphytic cactus with a climbing or creeping habit adorned with short and fine thorns. The plant undoubtedly produces the largest flower among all cacti. Ephemeral, it blooms at nightfall. Its scaly fruits, called Pitaya or Dragon Fruit, sometimes found on exotic product stalls, are yellow, with white flesh and tiny black seeds. It is a very frost-sensitive plant that requires at least 10°C in winter, and it blooms with difficulty in our regions, although it is possible with ideal growing conditions. One should not expect to eat its fruits in our latitudes. It is cultivated in full sun, in a pot to be brought indoors during the bad season, in a greenhouse or a conservatory. It requires a support or a trellis to spread its ramified lianas.

The Hylocereus megalanthus is synonymous with Cereus megalanthus or Selenicereus megalanthus. It is also known as Yellow Pitaya. This species belongs to the cactus family. It is native to the West Indies and tropical America: Colombia, Costa Rica, Ecuador, Nicaragua, Panama, and Peru. It is found in tropical forests and is an epiphytic and xerophytic plant. This large cactus is a highly branched liana that can reach 4m in length and width. Its stems can be lying on the ground, climbing or hanging. The stems often have a thickness of only 1.5cm and produce aerial roots. This cactus only blooms at nightfall, in the summer and autumn: a large white and yellow, tubular, fragrant and nectariferous flower blooms, but its duration is ephemeral: it starts to open around 9 pm and reaches its full bloom around midnight. The funnel-shaped flower measures up to 30cm in diameter and emits a vanilla scent. The stamens are numerous and inserted in two yellow areas; the style is yellow, and the stigma lobes are numerous and green. The self-sterile plant needs a companion plant and a pollinator to obtain fruits in its natural environment. Bats pollinate the flowers. The yellow-coloured pitaya fruit is oval and scaly, measuring about 10cm. Inside, its flesh is white with lots of tiny black seeds. It is low in calories, very refreshing, rich in vitamins and antioxidants.

The pitaya requires a sandy, gravelly, and humus-bearing soil. Outdoors can tolerate full sun exposure, provided it has good humidity and a warm, sheltered location. Flowering is challenging to achieve and depends on growing conditions. It needs a bright environment all year round, with good humidity. It tolerates heat very well and can withstand temperatures as low as -2°C for short periods. In winter, it is preferable to keep it between 10 and 11°C.

Unlike other cacti, this species should be considered more as a tropical or subtropical plant, and its environment should ideally be warm and humid.