Baptisia is an excellent 3+-ft. high border perennial. It's a late-spring/early-summer bloomer, likes full sun to half-day sun but can get leggy without enough sun.
It's a tough and vigorous perennial - once it is established. It grows deep roots, so it can unfortunately take a couple of years to reach its full effect.
The three new ones I planted in the fall are pathetic now, but next Spring they should be ready to show some vigor and bloom.
Many good things need patience. For instant color, go with annuals.