Why would they flower only once, in 2017? My grandmother planted mixed narcissus in 1916. I moved some of them to my garden, while they were blooming, 20 years ago, and they bloom for me every year here in Massachusetts, with minimal care. Most of the narcissus I have bought over the years return. They think they are trees. There ought to be a salubrious coldish winter near the Irish sea. I grew them in Minnesota and have seen them growing lushly in Iceland. They might be really unhappy in a warm place, though.