Beginner Gardening: New beds - Need planting advice, 0 by malsdad

malsdad wrote:
As you see in my picture, I have just planted a long line of arborvitae and have provided a bed the entire length. The picture doesn't show the entire length. I want to have a good show of black eyed susans and purple coneflower as the main backdrop and some smaller flowering border plants along the front of the beds. So.... How should I space the susans and coneflower? Should I do 10 feet of one and then 10 feet of another or what? What makes the nicest appearance? How big does one rooted plant get? Any ideas for the front low flowering plants? Any and all ideas welcome. As you can see, I have a huge area to fill :)

Also, I see bare root susans and coneflower(2nd & 3rd season) for sale online rather cheap. Should I go this way or spend more money on a more established plant?

Thanks!

Rod