Verbascum

The colors are simply stunning, which is why people keep trying to grow this as a cut flower. They have a downside, which is that they shed their petals VERY easily. Hilary of Morey Hill Farm suggests cutting them in bud, just before they open to extend vase life. An anti-ethylene post harvest treatment may work as well. These are probably best used in event work where vase life is less important, but be forewarned, they may make a mess. A beautiful mess.  Short lived perennial, zones 5-8