Habitat: South-center America , tropical and subtropical Africa and Asia.
Cultivation: The Cereus plants generally want high temperatures (never below 10 ° C), exposure in full sun, watering every 3-4 days in the summer but always being careful not to create standing water.
Curiosity: It produces, as fruit, fleshy berries that in many species are eatable. The name comes from the Latin cereus, that means candle, and refers to the shape and style of the stem, erect and columnar.
CEREUS KEY FEATURES
The Cereus is easy to cultivate and it is characterized by a rapid growth, this cactus is very popular either for the elongated stem, like a pillar, and for its large and spectacular flowers. Like all cacti, they are perennials and long-lived. The stem is dark green or bluish, wide, with evident grooves and thorns instead of leaves. In some species it stands straight as a candelabrum, in other it branches at the top. It can reach several meters in height even if grown in pots, but if planted directly into the ground the development is even more impressive: you can find plants of 10 or even 12 meters high. The Italian climate allows these plants to survive outdoors only in some areas of southern Italy, particularly in Sicily. Like all cacti, it is devoid of branches and the flowers grow directly from the stem, growing from the areolas. But they are rare in plants grown in pots, that only flourish if they have reached big dimensions. The flowers are large, with a very strong visual impact. They are white, pink or red, with well-arranged and spiral shape petals and sepals. They only open in the night and leave, as fruit, red or yellow berries, with blacks seeds, which are often eatable. Being hermaphrodites, all flowers produce, once withered, their fruit.
VARIETY AND TYPES
The genus Cereus is from Central and South America but from there it has spread to the tropical and subtropical area of Africa and Asia, giving life to new species or variants. Today, we can say that this kind of cactus includes about forty, fifty different species, according to the classification considered: the classification of individual species, in fact, continues to vary and often it varies from author to author.
We list some of the main species:
- Cereus aethiops
- C. forbesii
- C. hankeanus
- C. jamacaru
- C. jusbertii
- C. lamprospermus ssp. colosseus
- C. peruvianus
- C. validus
TIPS FOR GROWING
The plants of the genus Cereus are relatively easy to cultivate even if (like all succulents, and even more for cacti) you must be very careful to water stagnation. In Italy they are usually cultivated in pots, so they can be sheltered during the winter. In some southern regions, however (especially in Sicily) they can also survive outdoors.
These are our guidelines for a proper cultivation:
- The Cereus want an exposure in full sun, possibly to the south. The ideal is a point well-ventilated but without cold drafts. Too light color of the stem will indicate that the plant is not getting enough light.
- The temperature should not drop below 10 ° C.
- We recommend to water every 3-4 days in the summer, rather abundant, but making sure that there is not standing water. In the fall the watering can be gradually reduced and entirely or almost stopped in winter, when the plant is dormant.
- The soil should be light and well-drained: a specific soil for cacti, possibly with the addition of a little of coarse sand, it is the best choice.
- The plant has a very vigorous growth, so it’s good to fertilize quite often (once every 15 days) with compounds containing nitrogen, phosphorus and potassium. Please use, however, minimal doses of fertilizer – about one-third compared to the recommended dose on the packaging or less.
- To encourage the growth of the plants is recommended to repot every year in early spring, being careful during the operation that might be not easy because of the thorns! The clay pots are preferred because they promote the transpiration of the plant.
The Cereus reproduce either by seeds and by cuttings. The fertile seeds are produced from the fruits, that we remind, come from hermaphrodite flowers. The cuttings may be obtained instead … shortening the plant in half! Just cut a portion of the stem, leave it in the open air until the wound has not healed (it can take from 24 hours to a few weeks) and subsequently repot it. An lover may want to cut the cuttings at the top of the stem, to limit the impact on the existing plant. However we do not recommend it, and instead we suggest to intervene more or less to half the height of the plant, because it is such portion that has got more possibility to take root properly, developing well either the roots and the aerial part.