Irises are a nice filler for the perennial beds too. Easy, easy to grow, divide and plant. I have several iris roots that I completely forgot about from a friend that I threw on the ground last year and now they are growing perfectly happily right where I threw them. Folks around here give them away all the time. They fill in a space pretty quickly too!
Iris for free is awesome!!
To order them is nearly 20 bucks each.

A few years ago I came home from work to find someone stepped off in my flowerbed and cut every bloom off my black iris.