I had a heck of a job growing this. I collected the seed a few years ago from a garden I was working on, left them in a draw and forgot about them, found them again and sowed them in the coldframe the autumn before last. Finally they germinated the following spring, I potted them on and nurtured them - they seemed to reluctant to grow but eventually I got them to a size where they could be planted out. I was feeling pretty pleased with myself. I now learn that they will probably spread like wildfire and indeed are looking extremely robust and have been flowering their hearts out for a while now.
It's just as well then that I'm crazy for the smell of them and that they'll go down well with the bees and butterflies and moths. And after all it's these little triumphs that make gardening worthwhile. If it does take over the plot I may have to rethink that.