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.
Rubus hayata-koidzumii
This plant can be susceptible to overwatering, however, which can cause root rot in wet or heavy soil and good drainage is important.