Raspberry Truffle Coneflower Seeds Beautiful Summer Blooms Fresh Early July the first petals of the dark flower buds show their soft red color. Hummingbirds keep on coming to this one! Zones: 4-9 The center of the flowers remain dark until the flowers have entirely developed. The firm flowers are fairly horizontal. Mature Height: 32 inches Mature Width: 30 inches Bloom Size: 3.5" Form: Upright Growth Rate: Fast Seed starting instructions included.