ylocereus undatus is a sprawling or vining, terrestrial or epiphytic cactus. The stems are green, 3-winged, up to 16.5 feet (5 m) long and up to 3 inches (7.5 cm) wide. They climb by use of aerial roots and can reach up to 33 feet (10 m), growing on rocks and trees. Margins are horny and undulate with wings that are up to 2 inches (5 cm) wide. Spines on adult branches are 1 to 3, grayish-brown to black in color and up to 1.2 inches (3 cm) long. The scented, nocturnal flowers are greenish-yellow or whitish, rarely rose-tinged with green, outer tepals and bracts, up to 14 inches (35 cm) long and up to 12 inches (30 cm) in diameter. The fruit is oblong to oval, up to 5 inches (12.5 cm) long and up to 3.6 inches (9 cm) thick.
Dragonfruit (Hylocereus Undatus Cactus )
Like most cacti, Cereus are fairly low-maintenance and hardy. Make sure they receive enough water without becoming waterlogged, especially during the summer, and fertilize them for best results. If the roots have become black or overly soft, the cactus could be experiencing root rot – cut away the affected parts and replant. Most gardeners interested in cacti should be able to cultivate these without much problem.
It may become necessary to repot your Cereus if it outgrows its container. If so, make sure the soil is dry and then remove the pot. Knock away old soil and prune away any rotted or dead roots, then replace it in a new pot and backfill with new soil. Make sure not to overwater cacti planted in new pots, as this can lead to root rot – it should be left dry for about a week and then watered lightly