Each year I too enjoy drying assorted flowers from my garden. The purple coneflower is a great cut flower, but it really won't dry satisfactorily. The petals really don't hold well-they collapse and wilt-even if you try some of the drying agents like silica sand-they'll probably just fall away. You will have just the center, "bristle" cone. I've researced drying butterfly bush flowers, but cannot find any recommendation for that..I believe it may not hold up either-those tiny flowers may quickly collapse. The celosia is a wonderful flower for drying-it's easy to do-simpy cut them and hang them upside down in a dry place, out of direct sunlight. If you use sand, it is difficult to remove the grains without injuring the fuzzy flower clusters. Now, the flower cluster may be stiff and matted. I have read that you can overcome this by holding it over the spout of a boiling teakettle. Let the steam pass quickly over the flower cluster as you turn it in all directions. The cluster should fluff up quickly. Move the flower away from the steam and then hold it for about 1 minute; the flower should become dry again.
