Rob, I have a plant probably half the age of yours, but it is shy to set seed (I've grown it in the past from Jelitto seed, but it does seem to vary a lot from different sources). From when it first emerges with those wonderful buds, to its high point of flowering, it is one of, if not the, finest plants in the garden - visitors always drool over it! A friend has given me the hybrid P. x smouthii, but this lacks the exquisitely cut foliage of tenuifolia. I wonder if there are any other hybrids?