Eryngium Giganteum - Miss Wilmott's Ghost
This is one of the most impressive summer plants you can grow in the UK, with unbelievable metallic silvery-blue leaves, flowers and stems. The word gigantea refers to the flowers, not the plants which are rarely more than 2 feet high.
Seeds can be sown no matter what time of the year it is, they depend on having several months in cold, damp compost, before they will germinate. Keep the seed tray e.g. in a greenhouse or shady corner. These fresh seeds can be slow to germinate but do not use any artificial heat in an attempt to germinate them as it will simply disrupt their germination mechanism causing them to enter deeper dormancy.