I need to do some spot screening of the road and neighbors in 4 spots in my very traditional style and smallish yard. I've not used grasses anywhere. I want to be careful about incorporating them into my old fashioned style garden. I don't want them to stick out like a sore thumb. (I have lilacs, peonies, delphinium, iris.) My house is a large victorian, but the yard is small

I say annual to avoid the spread/dividing issue. (I just wrestled two huge siberian irises out of the garden yesterday!!)

I'd like something 5-8' tall. I did see the great Chicago photo of the P. Prince, but how long would it take to reach this size? I can link to some photos of the yard if that would help.

TIA for any ideas