You Will Get 5 Seeds Echinacea Sombrero Series Orange Coneflower. This very popular perennial that is hardy to USDA zone 3, and boasts unique orange flowers, and they bloom for a very long time.. They start blooming in summer, and they continue through fall, well beyond frost.. The plants usually grow to about 2 feet high, and they slowly spread to make bigger clumps. You may also find volunteer seedlings around the original plant.. This is a wonderful choice for a perennial with colorful flowers and an extremely long flowering period.