The spiral cereus (Cereus forbesii cv. Spiralis ), is a shrubby or treelike species dubiously thought of as a mutant Cereus forbesii. It is a heavy bloomer and large purple fruits are easily produced when flowers are pollinated.
It is a (usually) trunkless cactus that forms numerous tall, ascending, columnar stems which branch at the base in a candelabra-like arrangement. Stems have a waxy bloom on the surface and reach a height of 2-4 metres (but can grow up to 5 m high or more), and are 10 to 12 cm in diameter. They have five to nine widely-spaced ribs. A few branches from the original plant were imported in Europe around 1980 for a very high price. The original clone was characterized by strong grey stems covered with a dense pruina coating and with short spines (Also known as "short spined clone"), but nowadays almost all the plant on the trade are seed grown specimens derived from cross pollination with (presumably) Cereus peruvianus or Cereus stenogonus, they are usually a darker blue-green colour usually with longer spines, and there remains a considerable confusion surrounding the true identity of this plants.
Water regularly in summer but allow to dry fully before watering again. During the winter months they should be rather kept dry.
Prefers bright light and is happy with some direct sunlight once established, however too much direct sun may cause scorching.
Choose any well-drained soil mix for succulents. You can also use a mixture of equal parts peat moss, potting soil and sand or perlite.
Fertilize the plant once every month from March through August, using a balanced, water-soluble fertilizer. Mix the fertilizer according to label directions. Always apply fertilizer to damp soil, as fertilizing dry soil may damage the plant.
Average household temperatures 16-24°C will do. Can tolerate low temperatures but preferably keep above 8°C. Make sure they are not exposed to freezing temperatures (hardy to -2°C) or they may die.
Cereus cactus performs well in an unglazed ceramic or terracotta pot. The porosity of the pot provides air circulation around the roots, and the weight of the pot provides stability. Ensure the container has a drainage hole in the bottom, as the plant will rot without proper soil drainage.
