Hi Ashley,
I got these particular plants as young seedlings (2 years old) from Gordon Summerfield, though have raised new plants myself from seed off of these plants.
I've grown various Gethyllis species for 12 years now and I don't find they need any particularly special treatment - as you say, sharp drainage is a must and a warm, completely dry summer. When in growth, I water them rather as if they were cacti - give them a good soak but then let them dry out between waterings. Mind you, don't leave them too dry for too long between waterings as they will visibly wilt. They are in deep clay pots plunged in a sand plunge bed. As you can probably make out in the photo, I don't plunge their pots right up to the rims but rather let them stick out a few inches which I think helps the pots dry out a little quicker after watering. Though the flowers are rather fleeting they are wonderful while out and many species have attractive, ornamental or interesting leaves which give pleasure for the rest of the growing season.
Paul
