Hylocereus megalanthus
| Light | Bright, filtered light to gentle full sun; shade from harsh midday sun in hot climates |
|---|---|
| Water | Regular through the warm growing season, letting the mix dry a little between soakings; much drier in winter |
| Soil | Rich but free-draining mix with plenty of organic matter (see Soil and potting mix) |
| Temperature | Frost-tender; happiest above 10 °C, roughly USDA zones 10–11 |
| Propagation | Cuttings (fast and reliable); also seed |
| Toxicity | Non-toxic to cats and dogs; the fruit is edible |
Hylocereus megalanthus is the yellow-skinned, white-fleshed dragon fruit, widely regarded as the sweetest of the commercially grown pitayas. A sprawling, climbing cactus native to tropical Central and South America, it is grown both as a productive fruit crop and as an ornamental in the Hylocereus group, and is commonly sold under the names yellow dragon fruit and yellow pitaya. Many botanists now place it in the genus Selenicereus (as Selenicereus megalanthus), reflecting its close ties to the night-blooming moon cacti, though it remains best known to growers under its Hylocereus name.
Description
Hylocereus megalanthus is a vigorous, epiphytic and climbing cactus with long, jointed, three-angled green stems that scramble over rocks and up tree trunks, anchoring themselves with aerial roots. Compared with the more familiar red-fleshed dragon fruits, its stems are generally more slender and its ribs are studded with small clusters of short spines on the areoles — a distinguishing feature, as the red and pink types are typically nearly spineless.
The flowers are spectacular and among the largest in the cactus family: huge, funnel-shaped, creamy-white blooms that open for a single night and are heavily fragrant. The resulting fruit is oval, bright yellow and covered in small clustered spines that are usually rubbed off before sale. Inside, the translucent white flesh is dotted with tiny edible black seeds and is prized for its sweet, mild flavour — the trait behind the yellow pitaya's reputation as one of the best-tasting of the group.
Distribution and habitat
The species is native to northwestern South America and parts of Central America, including Colombia, Ecuador, Peru, Venezuela, Panama and Costa Rica, where it grows as a climbing epiphyte and lithophyte in humid, forested country. It clambers over host trees and rocky outcrops, rooting into pockets of leaf litter and mossy debris rather than deep soil, from lowland forest up into cooler Andean valleys.
It is now cultivated well beyond its native range, with commercial plantings across tropical and subtropical regions of South America, Asia and elsewhere, where the yellow pitaya commands a premium for its flavour.
Cultivation
Being a tropical climber, H. megalanthus wants warmth, humidity and something to scramble up. Give it a sturdy trellis, post or frame, as the heavy stems need support and fruiting is improved when growth is trained upward into good light. Grow it in a rich yet free-draining mix with generous organic matter — unlike most desert cacti, this is a comparatively thirsty and hungry plant during the warm months.
Water regularly through the growing season, letting the surface dry slightly between soakings, and feed lightly while in active growth; then ease right back in winter, keeping the plant just barely moist and, above all, frost-free. It is thoroughly frost-tender, so in marginal climates it is best grown under cover or brought in for winter. See Watering and Repotting for general technique.
A key point for anyone hoping for fruit: the huge flowers open for a single night and are pollinated by nocturnal visitors such as moths and bats. Unlike many red-fleshed dragon fruits, which are self-incompatible and need a second clone to fruit, the yellow pitaya is largely self-fertile; even so, many growers gently transfer pollen by hand in the evening to improve fruit set and size.
Propagation
Cuttings are the fastest and most popular method, and the usual way named fruiting selections are kept true. A healthy length of stem is cut, allowed to callus for several days in a dry, shaded spot, then set in a free-draining mix to root; cuttings establish readily and reach fruiting size far sooner than seedlings. See Propagation — cuttings.
Seed is also viable and is easily collected from ripe fruit, but seedlings are slow and variable, so this route is mostly used for breeding or curiosity rather than reproducing a particular plant. See Propagation — seed.
Common problems
- Rot — the commonest killer, from a soggy mix, poor drainage or cold-and-wet winters; stems soften, yellow and collapse.
- No fruit set — often improved by hand-pollinating the night flowers in the evening, even though the plant is largely self-fertile.
- Cold damage — even a light frost scars or kills the stems.
- Pests — mealybugs and scale shelter along the ribs and in the areoles, and slugs or snails may rasp at tender new growth.
See also
- Hylocereus — the genus overview
- Propagation — cuttings · Propagation — seed · Soil and potting mix · Watering · Repotting · Pests and diseases