I have several in the ground, as for them being difficult to grown in the ground--I'm not sure. I guess it depends what you mean. Like they don't always look great, I have one that flowered last year that just continues in its half dead way. I have another one that didn't flower as much and had 5 new culms in Sept/Aug, but now its gone yellowish in color.

I think the thing is with these is that when they look good they look really good, when they look bad they look really bad. I don't find 'growing' them to be difficult though.

Pura Vida

Here is a link that might be useful: Garden Blog with Pictures

Thanks for the info.