According to the ATP members map we have
a few three other members who live in South Africa.
How about a shout out to them to see if they can give you some help with the indigenous South African plants.
@cathyweid
@riette
@Elsa123
The following two members show up on the map as being in South Africa, but...
@conifers Nope, she's in Iowa.
@gardenersdetective Nope, zone 5 somewhere in the US?