Hi chrissie. Could it be Phlox paniculata White Admiral? Whatever it is its very pretty.
I have a couple of white ones like that too - one is Danielle and one is David. I have lots of other colours too - they keep everthing very colourful in July and August - love them. And pretty easy too - slugs ignore them and once you've given them a bit of a weed in spring they pretty much look after themselves
Hi Chrissie, I have lots like that - can't remember all their names but Bright Eyes, Amethyst, Laura, Tenor and Orange Perfection (which is actually pink not orange at all) are some. All of mine have come from Hayloft bareroot plant collections over the years - they bulk up very quickly from quite small plants. Never tried root cuttings, but I have divided successfully and taken softwood cuttings.