Before you buy an electric hedge trimmer, I'd suggest you rent one to cut your grasses next year, to be sure it does the job. The last time I shopped for hedge trimmers was several years ago, but the electric models were definately not up to the same work as gas powered models.

If you have a chipper/shredder, there's no reason why you couldn't shred the trimmings, and use them either as mulch, or compost them. I doubt if one of the light-weight string-trimmer leaf shredders would handle the Miscanthus, but I know a real C/S will, because I shred mine. I have a 10HP Troy-Bilt, and it has a problem taking a full hopper of OG stalks, but If I'm patient, it does a fine job. I can shove a 4" diameter bundle into the hopper, and it gobbles it right up.

Ramiro,

The only thing I'd add to what Donn said is the following tip:

Get a friend and take a length of rope or bungee cord and walk it around the clump, about half-way up. Then pull it tight and tie it off. This makes it really easy to haul-off or move the bundle of foliage after trimming. Here's a link to a better description of this technique...

Here is a link that might be useful: Cutting Back Ornamental Grasses

The electric hedge trimmers work just great for me. Such an improvement over cutting back with hand pruners or shears!
As for what to do with the cuttings ~ chipping/shreading and reuse is a great idea. Freshly chopped OGs can be used just like straw as a mulch. We use this on around the pepper plants and the tomatoes. It keeps the soil at even moisture & temperature.
Over time (about twice as long as leaves or other compost) it will break down and make usable compost.
I feel so much better about my grasses knowing I am not adding them to a landfill!

A.

That's a good idea, A. Do you use them full length, or shorten them?

I'm still casting about for a good mulch for veggies. This year I tried pine straw, but I found that although they keep Slugs away, they seem to encourage Earwigs and Sow Bugs, which were a big problem this year.

Donn,
We have a handy dandy machine called a bale chopper. Put the grass stems in and out comes something chopped finer than baled straw. Many of the OG species are stiffer/tougher than straw from cereal grains. Because of this it breaks down slower and equals a very good mulch. After doing its job as a mulch on the veggies we leave it over the winter and then just turn over the bed.

I imagine that any mulch would provide a hiding place for earwigs ~ but what goes around comes around and next year, hopefully, something will turn up in the garden to eat those pesky insects :o)
Just a gardener's wishful thinking .....

A.