In article , david@abacus-
nurseries.co.uk says...

Why is it that Nerine bowdenii and other Nerines go dormant and will
remain so for several years?
David @ a wet and windy side of Swansea Bay

My shocking-pink nerines have never missed a year for over a decade,
multiply slowly and are all in full flower right now, one lot in a big
pot and two other patches in the garden which have been badly overgrown
by other plants but seem to be indestructible.

I have several other nerines which are much less obliging;

A very pale pink one, which has just flowered for the first time (at
least 5 years after planting; in fact I'd forgotten it), and a pot of
red ones (same vintage) which produce healthy leaves every year but have
never flowered at all. I don't know what happened to the white one
(certainly it never flowered) and can't remember where I planted it.

Janet