Here's a beautiful combination I saw the other day of late summer native perennials in a garden at the Niagara Parks' Botanical Gardens.
It's a relatively "hot" combination (i.e. hot colours) with the red Lobelia cardinalis (Cardinal Flower), the orange Helenium (Helen's Flower), and the yellow Solidago (Goldenrod -- looks like 'Fireworks' just beginning to open).
"Native" plants are all the rage in gardening circles, particularly those with an environmental consideration. I'm not a big "tree-hugger" but I do believe that the use of native plants makes sense for most gardeners. In a nutshell, I will support the fact that plants that originated in North America will generally be easier to grow in our gardens. Of course, we still have to take sun/shade (i.e. prairie/woodland), and other variables on occasion, into consideration.
In any case, this is a great combination with lots of colour for late summer and early fall.
Here's to dirt under your nails.