By the name trichocereus some dozen species of tubular cactaceae, with columnar development, of Central American and South American origin were indicated; practically all the trichocereus have been identified as species belonging to the genus echinopsis, but the old name still remains in use, in that it identifies practically all the echinopsis with columnar development, to differentiate them from the round-developing species.
These are large cacti, which can reach a few meters in height, often whole-bodied, some species have numerous branches of the main stem, others tend to settle at the base. In nature, the walruses develop in large "bushes", which occupy some even a few meters in diameter, with some specimens developing side by side.
The name trichocereus means hairy cactus, or cactus with hair; It is due to the fact that most of the species, in addition to the dense sharp spines, also have different types of hair, often very pronounced.
These cacti are therefore cultivated like echinopsis, belonging to the same genus; in fact often these are very large plants, or in any case, they tend to develop with a certain rapidity, it is therefore good to prepare for frequent repotting, to prevent our cactus from falling due to the wind.
They prefer quite sunny positions, even if the hot summer sun can cause burns on the stem of some plants; the ideal climate is hot and dry, with regular watering from May to September, which will be provided only when and if the soil is completely dry.
Like most cacti, trichocereus also endure long periods of drought without any problems, while water stagnation can quickly favor the onset of fungal diseases, often fatal for the plant.
We therefore grow our cacti in a poor, stony, very well drained soil; we can prepare a good soil from citrus soil, now available in any nursery, to this soft and porous soil we add pearlite, pumice stone or lapillus, in order to make the final substrate very light and drained.
Some species of echinopsis are born on the slopes of the Andean mountains; for this reason some species are well suited to live in the garden, in the open ground, enduring even very low temperatures, and even frost. In these cases, these are slightly less susceptible to rotting cacti than others, and therefore they can withstand the presence of water in the soil even in cold weather.