I am very happy to encourage tall poppies in the garden. These are all free gifts and I accept them gladly.
I spent years trying to establish opium poppies (papaver somniferum, which is what these are*) but they are very capricious and the seeds can lie dormant for years, often requiring some sort of major soil disturbance before deciding to germinate. They can flower in profusion one year, then apparently disappear for several more, before reappearing seemingly at whim. These are all descended from a few seed heads from a friend's seaside garden, and have suddenly sprung up this year in the patch where we grew tulips (which we pulled out a short while ago), and all without me having to lift a finger. They won't last long, but they are the tallest poppies ever to self-seed here - at least waist-height on me - and for a brief moment they look like a carefully orchestrated field of poppies. There are also some red field poppies (papaver rhoeas) in there, from the time I shook a bag or two of seeds over the waning tulips. If I were being really demanding, I'd also like some of the dark or pink double/frilly/ fringed opium poppies, but they have not flowered this year (I know some are lying dormant around the place because they've bloomed in previous years).
My mother-in-law used to call the dried out stems and heads full of tiny seeds 'magic wands', and she was right.
*Oriental poppies (papaver orientale) are much easier to grow from seed or as bought plants. 'Patty's Plum', in a shade of somewhat washed-out brownish mauve, was one of the most modish poppies of recent years, but I prefer the pale pink and coral versions (eg 'Princess Victoria Louise' and especially 'Cedric Morris'), although this year I've been surprised by the pillar box red, fringed 'Turkenlouis' which I don't remember buying, but is spectacular. My money is now on the gorgeous 'Watermelon' as the next big thing in Oriental poppies.