Myrna's Garden in Mid-summer, Kale in the border,  coral coloured geranium, ornamental grasses,

Tip: Because geraniums need sunlighty, and grasses drape shade over the flowers, tie the grasses up like a pony tail  with natural coloured twine (or even a piece of long grass)and this contains the shade and keeps the geraniums blooming

One of my favourite plants is Kale. This is a long lasting annual, which becomes brighter in colour  in the colder months. The most economical way to buy is  in the beginning of the growing season, when it can be purchased as a regular plant in a 4 or 6 pack just like other annuals. (usually 1.29 for the pack)
They grow large and are great in borders. Leave room for them to grow, or  you can plant flowers in between them to give colour until the Kale becomes big and colourful. (Then they will hide the flowers in between but that is the whole point)

It can also be purchased pre-grown, large size at the end of summer or beginning of fall and that is approximately 10 dollars per plant.