Autumn Flowers in the Garden.

 We call this Gallipoli Heath and the pink one grows very well, flowering at a time when a lot of the other plants have finished. However, I have tried on 3 occasions to grow the white one, but it always dies.  Why?

 I have the common blue version of this Spur Plant and also the white, but this pink one is more unusual.
One of the Sedums (below) that flower at this time of the year.