You can't "trim" it from the top without making it look terrible with brown edges. The best you can do is dig up the plants that have spread too far or replace it with something else.

That's what I was afraid of. I would love a dwarf monkey gras but because of the color of my hedges, I really need something that is variegated. I guess I better start googling. Thanks!

There's a Black Mondo Grass - Ophiopogon planiscapus 'Nigrescens' - that might look spectacular there. Here's a shot from a garden in Scotland (zone 8, believe it or not) of a bed of Black Mondo.

I trim mine from the bottom up and turn them into small trees. Especially with the droughts we've all experienced, in my opinion, you can't get enough shade. Once you trim them into trees, you can plant shade-lovers underneath them.

Deb

Deb, That's a good idea but the tree thing wouldn't work for me because I have it as a border.
fawn- I think those are nice but I also saw a silver mist mondo grass. I think that's what it was. My hedges are a dark green so I would want something lighter to contrast. Don't you think?

Oo, I really like that black mondo a lot. I was actually gonna go buy some variegated liriope for an low care area, but I think I'll go in search of this instead. Thanks :)