Trichocereus Grandiflorus “Torch Cactus” is similar to many other cacti – it requires little water and likes partial to full sun. The latter means that it’s best to be kept outdoors.Besides, with some newer hybrids growing up to 1-2 feet tall and 12 inches wide, the Torch Cactus may be a too bulky cactus for indoor keeping.The Torch Cactus is more cold-resistant than the typical cactus – it can survive in temperatures as low as 15 degrees Fahrenheit (-9.4 degrees Celsius). While it still won’t survive harsh winters, it can do pretty well in mildly cold areas if kept dry.
Water the plants well and allow them to dry before watering again. This species seems to do better with a little more water than most cacti. In fact, its cultivation requirements are really more like 'normal' plants than most other cacti.
Outside full sun, inside needs bright light, and some direct sun. During winter month, put them in a cool luminous place and encourage them to enter winter dormancy by withholding water and fertiliser over the winter as they will etiolate, or become thin, due to lower levels of light.
