Hylocereus undatus is now known as Selenicereus undatus, it is part of the Cactaceae family and its native range is Mexico to Honduras where it grows as a succulent epiphyte primarily in the seasonally dry tropical biome.
It is commonly known as dragon fruit or pitaya as it produces an edible fruit. It is valued for its long, jointed, climbing stems and large, dramatic, night-blooming flowers. This vigorous plant can clamber over other structures, producing aerial roots to anchor itself. Its most famous feature is the brightly coloured, often red or pink, scaly fruit, which contains a white, fleshy pulp dotted with tiny black seeds.
The genus name Hylocereus comes from Greek words meaning "wood-cactus," referring to its forest-dwelling nature. Selenicereus comes from the Greek Σελήνη (Selene), the Moon Goddess, this is in reference to the night bloom. The specific epithet is a Latin word meaning "wavy," describing the margins of its stems. Common names like "dragon fruit" or "pitaya" refer to its distinctive fruit.
Light: This plant thrives in bright, indirect light. While it can tolerate some direct sun, particularly in the morning or late afternoon, intense midday sunlight can scorch its stems. In a UK home, a bright spot in a conservatory or near a sunny window is crucial for healthy growth and potential flowering.
Water: Water moderately during the active growing season (spring and summer), allowing the potting mix to dry out somewhat between waterings. Ensure good drainage to prevent waterlogging, which can lead to rot. Reduce watering significantly in autumn and winter when the plant is less active. Despite being a cactus, it appreciates more regular watering than desert cacti when in growth.
Soil: A well-draining, airy potting mix is essential. A specialist epiphytic cactus mix, or a blend of general potting compost with ample perlite and orchid bark, is ideal to mimic its natural growing conditions and ensure proper aeration.
Fertilising: Use a diluted liquid fertiliser every three to four weeks during the active growing season (spring and summer). A fertiliser formulated for cacti or orchids is suitable. Reduce or stop fertilising during the cooler, dormant months.
Temperature: This cactus prefers warm temperatures, ideally between 18-29°C during the growing season. It is not frost-tolerant and must be protected from temperatures below 10°C, which can cause damage. If grown outdoors in the UK, it should be brought indoors before temperatures drop.
Humidity: Selenicereus undatus appreciates moderate to higher humidity levels, characteristic of its native rainforest habitat. While it can adapt to average indoor humidity in the UK, occasional misting or placing the plant on a pebble tray with water can be beneficial, especially in drier indoor environments with central heating.
Growth Habit: It has a vigorous vining or climbing growth habit, with long, jointed stems that can extend significantly. As a hemi-epiphytic cactus, it produces aerial roots to cling to surfaces. Providing sturdy support, such as a trellis or post, is essential for its vertical development and to encourage fruiting.
Toxicity: Selenicereus undatus is generally considered non-toxic to humans and pets, with its fruit being widely consumed. However, like many cacti, its stems may have small spines or sharp edges, so exercise caution when handling to prevent physical injury. Keep it out of reach of children and animals to avoid accidental contact with any spines.