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.
Beautiful demoiselle
But natural waters with low water pollution can be in a state of the animals is not available. He may receive a water surface is not completely from the plants of the marginal vegetation to be overgrown, this is done mainly by fast-growing plants such as Meadowsweet ("Filipendula ulmaria"), the stinging nettle ("Urtica dioica") or Himalayan balsam ( Impatiens glandulifera ). The tree growth on the waters edge should not report closed canopy, otherwise lack the necessary sunlight.
Above all streams in uncultivated pastures, where no regular mowing is taking place, according to the animals are not habitable. This can be countered by regular removal of boundary vegetation, which will also not be complete. Even a partial thinning of trees and shrubs should be performed. In intensively used agricultural areas with a regular input of manure as fertilizer is a few meters wide can prevent extensive or unmanaged riparian strips one Einschwemmung and thus act against eutrophication.