Eryngium planum

Blue thistle is a perennial plant with blue flowers known to attract bees and butterflies. Grows fine on dry sandy soil.

Sowing instructions
Cross thistle is a light germinator. The seeds should not be covered with a layer of soil. Lay the seeds shallowly over the soil, press lightly and keep moist, but not wet. Give the seeds time to germinate, they need a cold period to germinate (stratification). Tip: put the seeds in the freezer for a few days, that way you can mimic that process.