Cornflowers and Californian Poppies
Good evening all!
A few weeks ago, I've sown Californian Poppies and Cornflowers in modules in my plastic greenhouse. They have germinated and they have a pair of true leaves. Why can't I plant them out in the garden before the last frosts? Are they not supposed to be hardy? What is then the difference between hardy and non-hardy plants since you can't plant anything out until after the last frosts. What about the poppies, nigella and calendula that have self-seeded outside?