how to prune diarama
By Casey
United Kingdom 
do you cut it to the ground like a pampas grass? if so when? how short.I know if you split it ,it may not flower for two years or more.
3 Sep, 2009
Answers
I leave mine alone and then in the spring i remove the dead stems/leaves. they can look tatty but when frosted they look stunning.
4 Sep, 2009
Do as Seaburngirl says that is absolutely the right thing to do.
4 Sep, 2009
My book just says to remove faded flower stems and foliage as it dies down.
3 Sep, 2009