Dyckia reitzii rubra

Dyckia reitzii is among  my chosen let aside the rubra one.
Well it does seem we have a lot to learn about it.
It seems there are more than one form of Dyckia reitzi rubra and 
they get real red but they need more than sun exposing to get intense and deep red.
They need to be exposed to freezing cold temperatures during the nights.
It is not the dry condition that leads this plant to its full glory.
In its habitat the soil is most of the time drenching wet.
 Winter is closer and closer here in Santa Catarina.
We shall see ...