Peruvian Torch, San Pedro
Natural Growing Conditions
Trichocereus pachanoi (San Pedro) is a very hardy species. It is grows to a height of 5m and will branch at the base forming a small tree, it has up to four small yellow to brown spines on each areole. It grows between elevations of 1000m to 3000m in the Andes. Its range extends throughout Peru, Ecuador and Bolivia. Trichocereus peruvianus (Peruvian Torch) has a similar range and habitat to T. pachanoi, although it is also cultivated on the coast of Peru. Unlike T. pachanoi, it has massive vicious brown spines, up to 10cm in length.
T. peruvianus is touted as containing ten times the mescaline found in T. pachanoi, although as far as I can tell, this is based on the evidence of one test, while others have produced converse results. Also, in some quarters it is claimed that T. peruvianus is far more water/sun tolerant and hardy than T. pachanoi, while K. Trout claims quite the opposite;
…mine tend towards black rotted spots unless watering is moderate and only in hot weather.
– Trout & Friends – The Cultivation & Propagation of Cacti
He also claims that T. peruvianus is more prone to sunburn under very hot sun. On these matters I am inclined to trust the experience of K. Trout. As yet my own experience of these two species shows little difference in growing requirements.
Growing from Seed
Most Trichocereus species are very straightforward to raise from seed. Please refer to the Growing Cacti form Seed technique.
Feeding and Watering
Unlike many cacti, some Trichocereus species respond very well to regular feeding and watering. T. pachanoi and T. peruvianus can both be given regular feeds throughout the growing season, and can be watered daily during the hottest parts of the Summer. Bear in mind though, that if kept damp through cold periods, they will invariably suffer. They should be watered only occasionally during the Spring and Autumn, unless it is unusually warm, and not watered at all during the winter months. Being wet during the winter will cause them to split as they expand with excess water, and they may rot and quickly die. In temperate zones, winter protection will probably be needed. This may involve bringing the plants indoors, but protection from the rain in the form of a makeshift roof or other cover should suffice.
They will produce prodigious amounts of growth each year if kept well fed and watered throughout the warmest months, particularly if they have been acclimatized to accept full sun. Once these cacti are established they can easily produce 30cm of growth every year.