Saxifraga Doctor Clay Saxifraga Doctor Clay Saxifraga Doctor Clay Intensely silver rosettes. £3.00 Out of stock. One of the brightest and most silver of all the silver encrusted Saxifrages we grow. It grows as neat, hard mounds of small to medium-sized rosettes which are entirely overlaid with silvery grey. Makes a superb specimen in a large clay pan or in a stone trough but would do well in a crevice on the rock garden. Stems of white flowers in summer on typical, long, arching sprays.