Description
Cleistocactus is one of the most popular cacti. It grows very slowly, but after some time it regularly produces large numbers of big red or yellow flowers. It comes from South America, where about 30 species grow, mainly on rocky ground, liking high air humidity. Some species can reach 2–3 metres in height, and the flowers can be 10 cm long. The stems of most species are slender and rarely branch. They are densely covered with tufts of white spines.
Unlike other cacti, Cleistocactus flowers form on both sides of the stem. They are tubular, often S-shaped, and red, orange or yellow. Each flower lasts 4–5 days on the plant.
Requirements
This cactus needs plenty of light, even in winter. Place it in a bright, cooler spot at about 10°C.
Propagation
Cleistocactus is propagated by cuttings in February–March, or from seed.
Care
This cactus is relatively easy to grow, as it has no special requirements regarding its surroundings. Like most cacti, it likes a sunny, warm position. To keep it growing evenly, turn the pot from time to time – except when buds and flowers are forming. The best growing medium is a special cactus compost containing plenty of nutrients.
December–February
During these months Cleistocactus rests. Keep it at about 10°C in a bright, dry place. Water and feed sparingly.
March–May
As the days lengthen, the rest period ends. In March move it to a brighter spot, where it will soon start to flower. This is the time to repot it if needed. You can also water more generously.
June–August
On sunny, warm days the cactus can be moved outside to a sunny spot. Water it regularly and feed it with a special cactus fertiliser. In summer mist Cleistocactus with lukewarm water.
September–November
Bring the cactus back indoors. At the end of September reduce watering and stop feeding. In autumn, too, the cactus needs a bright position.
When plants get sick
Rotting patches – overwatering. Cut out the rotting parts with a sharp knife.
Mealybugs – remove them with tweezers.
Before you buy
Average lifespan: it can live a very long time.
Difficulty of care: this cactus is simple and trouble-free to grow.