The label in the pot said "Tall White Daisies". My mum gave me the plant a couple of years ago when I moved in, and although I planted it last year it didn't do anything. This year it grew and grew, and had masses of tiny buds for weeks. I was intrigued to see what type of tall white daisies they would be. They obviously weren't leucanthemum, might they be a type of aster maybe? Gradually they opened and revealed themselves - not exactly tall white daisies, more of a tall golden rod! Not what I was expecting, but thanks mum as it does give some good autumn colour!
Golden Rod