Hi Pieter, Crinum luteolum appears to be a distinct species from the Andamooka or Desert Crinum of South Australia in the link. C luteolum grows in a mixture of heavy clay soil and rock , but still has a very hot and dry climate, getting about 250mm of annual rainfall. Despite their harsh environment both species seem quite amenable to cultivation remaining in growth while it is warm and there is moisture in the ground or their potting media. They respond to rainfall with increased growth and slow down or stop growing when it is dry. It seems likely they start and stop growing in their environment in response to rainfall . When I observed them in habitat in February and March this year their growth cycle from rainfall, flowering , fruiting, then dying back took only 6 weeks. Daytime maximum temperatures during this time were in the high 30'sC to low 40'sC. I suspect you will have no trouble growing them. Cheers, Rob in Tasmania