These perennial plants come back years after years. They are hardy and almost zero maintenance. $5/clump. I dig up a clump (about the size of 6"pot) and put in a container/bag for you.
Aster (pink and purple flowers)
Daylily (orange and purple flowers)
False solomon's seal
Yarrow (pink and red flowers)
Lily of the valley
Snow in summer
Sedum groundcover (yellow and pink flowers)