Cleistocactus strausii
Silver Torch cactus can thrive in low-nitrogen soil without facing the consequences of low nitrogen. Too much water will make the plant weak and lead to root rot. 
Least Concern. This cactus is locally abundant in its native land and has few local threats to its survival.
This cactus can be propagated by cuttings or seed.
Hydrozoning
As you move farther away from the water source your plantings require less water. For example, drought tolerant plants such as sage or cactus would not be planted in a bluegrass lawn, but would be separated, since bluegrass has a higher water requirement.