In article ekom.at,
Willi writes

I hope this did not happen when you photographed the stinging nettles.
Haha. Great shots btw. I had always some opium poppies too. I can
remember that I still had a few last year, but seemingly without
producing seeds for this year. I liked the doubled ones (as in your
pic), but they were quite rare (1 every other year or less).

They produce a lot of seeds and if you let them get into your compost
you get 100% germination in pots where you don't want them. But if the
seeds fall in flower beds you only get a few plants, so I suppose most
of them are eaten by birds or some other creature.
--
Sue ]