The more you cut it back, the faster it grows.

You can cut it back in late winter, before it's early spring growing season. You can then cut it back when it starts to look sloppy in the dead of summer, before it's fall growing season. If it doesn't look too bad, and you don't want to trim it, you can just tease out the dead foliage and bloom stems, using latex dipped gloves.

I never cut mine back, I just tease the dead foliage and dead bloom stems out wearing gloves.

Early Spring, I pull the blue fescue up in a pony tail and scissor trim. Then, when the seed heads are ready to be harvested I gather them again like a pony tail and cut for starting new plants. If the plant is look shaggy I'll just touch up trim.
Gave them urea last year, and had some osmocote around for the other perennials, Whoa did they like that! Blue, Blue Blue they were.

There were some years that the mice got to my Blue Fescue. When the snow melted I saw the mice had mowed the grasses right to the ground. They grew back with a vengeance and looked wonderful. Otherwise I've also cut them in early spring before growth starts.

Depends on what it looks like - I'll trim off long growth around the bottom that has turned brown and is dragging on the ground throughout the year. I always give it a close cropping in late winter - just did it, in fact, about 2 weeks ago. And by "close cropping", I mean I use a pair of very sharp garden scissors to shear it down to a nubbin...plant version of a military buzz cut. LOL. It looks a bit freakish for a short time -kinda like a hedgehog- but always grows back really fast and in a beautiful icy shade of blue. I have a grouping of 5 growing along with some 'blue spruce' sedum, and the combination produces a striking patch of blue in my garden.

Renee

Hi, new at this web, but would like some info on sowing blue fescue seed....Can a fall sowing be done in zone 4? or do I need to wait until next summer?

I need to know what implement to use to trim the blue fescue

Anything that will cut them--shears, pruners, anything that works.

I don't advise trimming them. Clean out the dead and let them fill in with new growth in spring, they go dormant in summer and look sort of peaked but come around in spring. They are also relatively short lived and prone to root damage by grubs, sometimes its best to let new plants replace old ones.

Anything that cuts will trim grass. I use grass shears but I've used regular scissors on small grasses too although thats hard on fingers if you have a lot to trim, you'll end up with blisters.